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Raspberry Jam Big Birthday Weekend 2018 roundup

Post Syndicated from Ben Nuttall original https://www.raspberrypi.org/blog/big-birthday-weekend-2018-roundup/

A couple of weekends ago, we celebrated our sixth birthday by coordinating more than 100 simultaneous Raspberry Jam events around the world. The Big Birthday Weekend was a huge success: our fantastic community organised Jams in 40 countries, covering six continents!

We sent the Jams special birthday kits to help them celebrate in style, and a video message featuring a thank you from Philip and Eben:

Raspberry Jam Big Birthday Weekend 2018

To celebrate the Raspberry Pi’s sixth birthday, we coordinated Raspberry Jams all over the world to take place over the Raspberry Jam Big Birthday Weekend, 3-4 March 2018. A massive thank you to everyone who ran an event and attended.

The Raspberry Jam photo booth

I put together code for a Pi-powered photo booth which overlaid the Big Birthday Weekend logo onto photos and (optionally) tweeted them. We included an arcade button in the Jam kits so they could build one — and it seemed to be quite popular. Some Jams put great effort into housing their photo booth:

Here are some of my favourite photo booth tweets:

RGVSA on Twitter

PiParty photo booth @RGVSA & @ @Nerdvana_io #Rjam

Denis Stretton on Twitter

The @SouthendRPIJams #PiParty photo booth

rpijamtokyo on Twitter

PiParty photo booth

Preston Raspberry Jam on Twitter

Preston Raspberry Jam Photobooth #RJam #PiParty

If you want to try out the photo booth software yourself, find the code on GitHub.

The great Raspberry Jam bake-off

Traditionally, in the UK, people have a cake on their birthday. And we had a few! We saw (and tasted) a great selection of Pi-themed cakes and other baked goods throughout the weekend:

Raspberry Jams everywhere

We always say that every Jam is different, but there’s a common and recognisable theme amongst them. It was great to see so many different venues around the world filling up with like-minded Pi enthusiasts, Raspberry Jam–branded banners, and Raspberry Pi balloons!


Sergio Martinez on Twitter

Thank you so much to all the attendees of the Ikana Jam in Krakow past Saturday! We shared fun experiences, some of them… also painful 😉 A big thank you to @Raspberry_Pi for these global celebrations! And a big thank you to @hubraum for their hospitality! #PiParty #rjam

NI Raspberry Jam on Twitter

We also had a super successful set of wearables workshops using @adafruit Circuit Playground Express boards and conductive thread at today’s @Raspberry_Pi Jam! Very popular! #PiParty

Suzystar on Twitter

My SenseHAT workshop, going well! @SouthendRPiJams #PiParty

Worksop College Raspberry Jam on Twitter

Learning how to scare the zombies in case of an apocalypse- it worked on our young learners #PiParty @worksopcollege @Raspberry_Pi https://t.co/pntEm57TJl


Rita on Twitter

Being one of the two places in Kenya where the #PiParty took place, it was an amazing time spending the day with this team and getting to learn and have fun. @TaitaTavetaUni and @Raspberry_Pi thank you for your support. @TTUTechlady @mictecttu ch




@GABONIAVERACITY #PiParty Lagos Raspberry Jam 2018 Special International Celebration – 6th Raspberry-Pi Big Birthday! Lagos Nigeria @Raspberry_Pi @ben_nuttall #RJam #RaspberryJam #raspberrypi #physicalcomputing #robotics #edtech #coding #programming #edTechAfrica #veracityhouse https://t.co/V7yLxaYGNx

North America

Heidi Baynes on Twitter

The Riverside Raspberry Jam @Vocademy is underway! #piparty

Brad Derstine on Twitter

The Philly & Pi #PiParty event with @Bresslergroup and @TechGirlzorg was awesome! The Scratch and Pi workshop was amazing! It was overall a great day of fun and tech!!! Thank you everyone who came out!

Houston Raspi on Twitter

Thanks everyone who came out to the @Raspberry_Pi Big Birthday Jam! Special thanks to @PBFerrell @estefanniegg @pcsforme @pandafulmanda @colnels @bquentin3 couldn’t’ve put on this amazing community event without you guys!

Merge Robotics 2706 on Twitter

We are back at @SciTechMuseum for the second day of @OttawaPiJam! Our robot Mergius loves playing catch with the kids! #pijam #piparty #omgrobots

South America

Javier Garzón on Twitter

Así terminamos el #Raspberry Jam Big Birthday Weekend #Bogota 2018 #PiParty de #RaspberryJamBogota 2018 @Raspberry_Pi Nos vemos el 7 de marzo en #ArduinoDayBogota 2018 y #RaspberryJamBogota 2018


Fablab UP Cebu on Twitter

Happy 6th birthday, @Raspberry_Pi! Greetings all the way from CEBU,PH! #PiParty #IoTCebu Thanks @CebuXGeeks X Ramos for these awesome pics. #Fablab #UPCebu

福野泰介 on Twitter

ラズパイ、6才のお誕生日会スタート in Tokyo PCNブースで、いろいろ展示とhttps://t.co/L6E7KgyNHFとIchigoJamつないだ、こどもIoTハッカソンmini体験やってます at 東京蒲田駅近 https://t.co/yHEuqXHvqe #piparty #pipartytokyo #rjam #opendataday

Ren Camp on Twitter

Happy birthday @Raspberry_Pi! #piparty #iotcebu @coolnumber9 https://t.co/2ESVjfRJ2d


Glenunga Raspberry Pi Club on Twitter

PiParty photo booth

Personally, I managed to get to three Jams over the weekend: two run by the same people who put on the first two Jams to ever take place, and also one brand-new one! The Preston Raspberry Jam team, who usually run their event on a Monday evening, wanted to do something extra special for the birthday, so they came up with the idea of putting on a Raspberry Jam Sandwich — on the Friday and Monday around the weekend! This meant I was able to visit them on Friday, then attend the Manchester Raspberry Jam on Saturday, and finally drop by the new Jam at Worksop College on my way home on Sunday.

Ben Nuttall on Twitter

I’m at my first Raspberry Jam #PiParty event of the big birthday weekend! @PrestonRJam has been running for nearly 6 years and is a great place to start the celebrations!

Ben Nuttall on Twitter

Back at @McrRaspJam at @DigInnMMU for #PiParty

Ben Nuttall on Twitter

Great to see mine & @Frans_facts Balloon Pi-Tay popper project in action at @worksopjam #rjam #PiParty https://t.co/GswFm0UuPg

Various members of the Foundation team attended Jams around the UK and US, and James from the Code Club International team visited AmsterJam.

hackerfemo on Twitter

Thanks to everyone who came to our Jam and everyone who helped out. @phoenixtogether thanks for amazing cake & hosting. Ademir you’re so cool. It was awesome to meet Craig Morley from @Raspberry_Pi too. #PiParty

Stuart Fox on Twitter

Great #PiParty today at the @cotswoldjam with bloody delicious cake and lots of raspberry goodness. Great to see @ClareSutcliffe @martinohanlon playing on my new pi powered arcade build:-)

Clare Sutcliffe on Twitter

Happy 6th Birthday @Raspberry_Pi from everyone at the #PiParty at #cotswoldjam in Cheltenham!

Code Club on Twitter

It’s @Raspberry_Pi 6th birthday and we’re celebrating by taking part in @amsterjam__! Happy Birthday Raspberry Pi, we’re so happy to be a part of the family! #PiParty

For more Jammy birthday goodness, check out the PiParty hashtag on Twitter!

The Jam makers!

A lot of preparation went into each Jam, and we really appreciate all the hard work the Jam makers put in to making these events happen, on the Big Birthday Weekend and all year round. Thanks also to all the teams that sent us a group photo:

Lots of the Jams that took place were brand-new events, so we hope to see them continue throughout 2018 and beyond, growing the Raspberry Pi community around the world and giving more people, particularly youths, the opportunity to learn digital making skills.

Philip Colligan on Twitter

So many wonderful people in the @Raspberry_Pi community. Thanks to everyone at #PottonPiAndPints for a great afternoon and for everything you do to help young people learn digital making. #PiParty

Special thanks to ModMyPi for shipping the special Raspberry Jam kits all over the world!

Don’t forget to check out our Jam page to find an event near you! This is also where you can find free resources to help you get a new Jam started, and download free starter projects made especially for Jam activities. These projects are available in English, Français, Français Canadien, Nederlands, Deutsch, Italiano, and 日本語. If you’d like to help us translate more content into these and other languages, please get in touch!

PS Some of the UK Jams were postponed due to heavy snowfall, so you may find there’s a belated sixth-birthday Jam coming up where you live!

S Organ on Twitter

@TheMagP1 Ours was rescheduled until later in the Spring due to the snow but here is Babbage enjoying the snow!

The post Raspberry Jam Big Birthday Weekend 2018 roundup appeared first on Raspberry Pi.

New PS4 Jailbreak Hits Firmware 4.55, Excites the Masses

Post Syndicated from Andy original https://torrentfreak.com/new-ps4-jailbreak-hits-firmware-4-55-excites-the-masses-180228/

Largely since the advent of the third generation of games consoles in the early to mid 80s, adventurous users have been interested in making their machines do things they’re not supposed to.

In common with the 8bit games-capable computers that preceded them, much emphasis was placed on piracy, with people seeking to cut console games costs with copies of what would otherwise be expensive investments. Alongside, however, was a rapidly developing “homebrew” scene in which often amateur coders sought to utilize their purchased hardware for non-conventional means.

These days the process of digitally cracking open a device is much more complex and has given birth to the term ‘jailbreaking’. It can be applied to devices as diverse as iPhones and PlayStations but it all means the same thing – the removal of restrictions put in place by manufacturers in order to control what can be done with a device.

These restrictions mostly relate to the running of software, with the big manufacturers wanting people to not only use ‘app stores’ that they control but also to pay for the privilege. The jailbreaking scene often aims to undermine the former but despite many good intentions, it often gets dragged into piracy as a result.

Yesterday there was cause for both homebrew coders and pirates-in-waiting to celebrate with the announcement that developer ‘Qwertyoruiop’ had released the full code for his PS4 firmware 4.55 kernel exploit.

While the release caused much excitement, the kernel exploit still needs a usermode entry point. As reported by Wololo, that could come via the Webkit exploit previously released by Qwertyoruiop for PS4 firmware 4.07 a while back.

So, to put things into basic terms, while the new exploit works up to v4.55, the user exploit only works up to those with PS4s running v4.07, at least until another usermode exploit for later firmwares is released.

But with anticipation in the air, a few hours later yet more exciting news appeared on the horizon. Taking Qwertyoruiop’s v4.55 kernel exploit and running with it, developer SpecterDev announced on Twitter that he’d published a full implementation of the exploit on Github.

In other words, SpecterDev has released a fully-functional jailbreak of PS4 firmware 4.55, which opens up a whole world of opportunities for the homebrew scene – and beyond. That being said, he’s careful to note on Github that others will have to step up to fill in the gaps from here.

“[The implementation] will allow you to run arbitrary code as kernel, to allow jailbreaking and kernel-level modifications to the system. This release however, does not contain any code related to defeating anti-piracy mechanisms or running homebrew,” he explained.

Nevertheless, SpecterDev’s code has an inbuilt ‘ear’ that can take instructions (a so-called ‘payload’) and do something useful with them.

“This exploit does include a loader that listens for payloads on port 9020 and will execute them upon receival,” he explains.

Rumors suggest that there’s already some kind of payload being shared privately. We haven’t been able to confirm what it does yet but people seem excited by it.

Update: Confirmation of what it does from Wololo: “When run in combination with the recently released exploit for PS4 4.55, Holy Grail lets users install and run unsigned packages. In practice, this will let 4.55 owners install and run homebrews as well as, yes, pirated PS4 games.”

A video showing the jailbreak in action has been uploaded to YouTube and can be seen below.

Source: TF, for the latest info on copyright, file-sharing, torrent sites and more. We also have VPN discounts, offers and coupons

The Early Days of Mass Internet Piracy Were Awesome Yet Awful

Post Syndicated from Andy original https://torrentfreak.com/the-early-days-of-mass-internet-piracy-were-awesome-yet-awful-180211/

While Napster certainly put the digital cats among the pigeons in 1999, the organized chaos of mass Internet file-sharing couldn’t be truly appreciated until the advent of decentralized P2P networks a year or so later.

In the blink of an eye, everyone with a “shared folder” client became both a consumer and publisher, sucking in files from strangers and sharing them with like-minded individuals all around the planet. While today’s piracy narrative is all about theft and danger, in the early 2000s the sharing community felt more like distant friends who hadn’t met, quietly trading cards together.

Satisfying to millions, those who really engaged found shared folder sharing a real adrenaline buzz, as English comedian Seann Walsh noted on Conan this week.

“Click. 20th Century Fox comes up. No pixels. No shaky cam. No silhouettes of heads at the bottom of the screen, people coming in five minutes late. None of that,” Walsh said, recalling his experience of downloading X-Men 2 (X2) from LimeWire.

“We thought: ‘We’ve done it!!’ This was incredible! We were going to have to go to the cinema. We weren’t going to have to wait for the film to come out on video. We weren’t going to have to WALK to blockbuster!”

But while the nostalgia has an air of magic about it, Walsh’s take on the piracy experience is bittersweet. While obtaining X2 without having to trudge to a video store was a revelation, there were plenty of drawbacks too.

Downloading the pirate copy took a week, which pre-BitTorrent wasn’t a completely bad result but still a considerable commitment. There were also serious problems with quality control.

“20th Century fades, X Men 2 comes up. We’ve done it! We’re not taking it for granted – we’re actually hugging. Yes! Yes! We’ve done it! This is the future! We look at the screen, Wolverine turns round…,” …..and Walsh launches into a broadside of pseudo-German babble, mimicking the unexpectedly-dubbed superhero.

After a week of downloading and getting a quality picture on launch, that is a punch in the gut, to say the least. Arguably no less than a pirate deserves, some will argue, but a fat lip nonetheless, and one many a pirate has suffered over the years. Nevertheless, as Walsh notes, it’s a pain that kids in 2018 simply cannot comprehend.

“Children today are living the childhood I dreamed of. If they want to hear a song – touch – they stream it. They’ve got it now. Bang. Instantly. They don’t know the pain of LimeWire.

“Start downloading a song, go to school, come back. HOPE that it’d finished! That download bar messing with you. Four minutes left…..nine HOURS and 28 minutes left? Thirty seconds left…..52 hours and 38 minutes left? JUST TELL ME THE TRUTH!!!!!” Walsh pleaded.

While this might sound comical now, this was the reality of people downloading from clients such as LimeWire and Kazaa. While X2 in German would’ve been torture for a non-German speaker, the misery of watching an English language copy of 28 Days Later somehow crammed into a 30Mb file is right up there too.

Mislabeled music with microscopic bitrates? That was pretty much standard.

But against the odds, these frankly second-rate experiences still managed to capture the hearts and minds of the digitally minded. People were prepared to put up with nonsense and regular disappointment in order to consume content in a way fit for the 21st century. Yet somehow the combined might of the entertainment industries couldn’t come up with anything substantially better for a number of years.

Of course, broadband availability and penetration played its part but looking back, something could have been done. Not only didn’t the Internet’s popularity come as a surprise, people’s expectations were dramatically lower than they are today too. In any event, beating the pirates should have been child’s play. After all, it was just regular people sharing files in a Windows folder.

Any fool could do it – and millions did. Surprisingly, they have proven unstoppable.

Source: TF, for the latest info on copyright, file-sharing, torrent sites and more. We also have VPN discounts, offers and coupons

Modding Legends Team-Xecuter Announce “Future-Proof” Nintendo Switch Hack

Post Syndicated from Andy original https://torrentfreak.com/modding-legends-team-xecuter-announce-future-proof-nintendo-switch-hack-180104/

Since the advent of the first truly mass-market videogames consoles, people have dreamed about removing the protection mechanisms that prevent users from tinkering with their machines.

These modifications – which are software, hardware, or combination of the two – facilitate the running of third-party or “homebrew” code. On this front, a notable mention must go to XBMC (now known as Kodi) which ran on the original Xbox after its copy protection mechanisms had been removed.

However, these same modifications regularly open the door to mass-market piracy too, with mod-chips (hardware devices) or soft-mods (software solutions) opening up machines so that consumers can run games obtained from the Internet or elsewhere.

For the Nintendo Switch, that prospect edged closer at the end of December when Wololo reported that hackers Plutoo, Derrek, and Naehrwert had given a long presentation (video) at the 34C3 hacking conference in Germany, revealing their kernel hack for the Nintendo Switch.

While this in itself is an exciting development, fresh news from a veteran hacking group suggests that Nintendo could be in big trouble on the piracy front in the not-too-distant future.

“In the light of a recent presentation at the Chaos Communication Congress in Germany we’ve decided to come out of the woodwork and tease you all a bit with our latest upcoming product,” the legendary Team-Xecutor just announced.

While the hack announced in December requires Switch firmware 3.0 (and a copy of Pokken Tournament DX), Team-Xecutor say that their product will be universal, something which tends to suggest a fundamental flaw in the Switch system.

“This solution will work on ANY Nintendo Switch console regardless of the currently installed firmware, and will be completely future proof,” the team explain.

Xecutor say that their solution opens up the possibility of custom firmware (CFW) on Nintendo’s console. In layman’s terms, this means that those with the technical ability will be able to dictate, at least to a point, how the console functions.

“We want to move the community forward and provide a persistent, stable and fast method of running your own code and custom firmware patches on Nintendo’s latest flagship product. And we think we’ve succeeded!” the team add.

The console-modding community thrives on rumors, with various parties claiming to have made progress here and there, on this console and that, so it’s natural for people to greet this kind of announcement with a degree of skepticism. That being said, Team-Xecutor is no regular group.

With a long history of console-based meddling, Team-Xecutor’s efforts include hardware solutions for the original Playstation and Playstation 2, an array of hacks for the original Xbox (Enigmah and various Xecuter-branded solutions), plus close involvement in prominent Xbox360 mods. Their pedigree is definitely not up for debate.

For now, the team isn’t releasing any more details on the nature of the hack but they have revealed when the public can expect to get their hands on it.

“Spring 2018 or there around,” they conclude.

Team-Xecutor demo

Source: TF, for the latest info on copyright, file-sharing, torrent sites and more. We also have VPN discounts, offers and coupons

Random with care

Post Syndicated from Eevee original https://eev.ee/blog/2018/01/02/random-with-care/

Hi! Here are a few loose thoughts about picking random numbers.

A word about crypto


This is all aimed at frivolous pursuits like video games. Hell, even video games where money is at stake should be deferring to someone who knows way more than I do. Otherwise you might find out that your deck shuffles in your poker game are woefully inadequate and some smartass is cheating you out of millions. (If your random number generator has fewer than 226 bits of state, it can’t even generate every possible shuffling of a deck of cards!)

Use the right distribution

Most languages have a random number primitive that spits out a number uniformly in the range [0, 1), and you can go pretty far with just that. But beware a few traps!

Random pitches

Say you want to pitch up a sound by a random amount, perhaps up to an octave. Your audio API probably has a way to do this that takes a pitch multiplier, where I say “probably” because that’s how the only audio API I’ve used works.

Easy peasy. If 1 is unchanged and 2 is pitched up by an octave, then all you need is rand() + 1. Right?

No! Pitch is exponential — within the same octave, the “gap” between C and C♯ is about half as big as the gap between B and the following C. If you pick a pitch multiplier uniformly, you’ll have a noticeable bias towards the higher pitches.

One octave corresponds to a doubling of pitch, so if you want to pick a random note, you want 2 ** rand().

Random directions

For two dimensions, you can just pick a random angle with rand() * TAU.

If you want a vector rather than an angle, or if you want a random direction in three dimensions, it’s a little trickier. You might be tempted to just pick a random point where each component is rand() * 2 - 1 (ranging from −1 to 1), but that’s not quite right. A direction is a point on the surface (or, equivalently, within the volume) of a sphere, and picking each component independently produces a point within the volume of a cube; the result will be a bias towards the corners of the cube, where there’s much more extra volume beyond the sphere.

No? Well, just trust me. I don’t know how to make a diagram for this.

Anyway, you could use the Pythagorean theorem a few times and make a huge mess of things, or it turns out there’s a really easy way that even works for two or four or any number of dimensions. You pick each coordinate from a Gaussian (normal) distribution, then normalize the resulting vector. In other words, using Python’s random module:

def random_direction():
    x = random.gauss(0, 1)
    y = random.gauss(0, 1)
    z = random.gauss(0, 1)
    r = math.sqrt(x*x + y*y + z*z)
    return x/r, y/r, z/r

Why does this work? I have no idea!

Note that it is possible to get zero (or close to it) for every component, in which case the result is nonsense. You can re-roll all the components if necessary; just check that the magnitude (or its square) is less than some epsilon, which is equivalent to throwing away a tiny sphere at the center and shouldn’t affect the distribution.

Beware Gauss

Since I brought it up: the Gaussian distribution is a pretty nice one for choosing things in some range, where the middle is the common case and should appear more frequently.

That said, I never use it, because it has one annoying drawback: the Gaussian distribution has no minimum or maximum value, so you can’t really scale it down to the range you want. In theory, you might get any value out of it, with no limit on scale.

In practice, it’s astronomically rare to actually get such a value out. I did a hundred million trials just to see what would happen, and the largest value produced was 5.8.

But, still, I’d rather not knowingly put extremely rare corner cases in my code if I can at all avoid it. I could clamp the ends, but that would cause unnatural bunching at the endpoints. I could reroll if I got a value outside some desired range, but I prefer to avoid rerolling when I can, too; after all, it’s still (astronomically) possible to have to reroll for an indefinite amount of time. (Okay, it’s really not, since you’ll eventually hit the period of your PRNG. Still, though.) I don’t bend over backwards here — I did just say to reroll when picking a random direction, after all — but when there’s a nicer alternative I’ll gladly use it.

And lo, there is a nicer alternative! Enter the beta distribution. It always spits out a number in [0, 1], so you can easily swap it in for the standard normal function, but it takes two “shape” parameters α and β that alter its behavior fairly dramatically.

With α = β = 1, the beta distribution is uniform, i.e. no different from rand(). As α increases, the distribution skews towards the right, and as β increases, the distribution skews towards the left. If α = β, the whole thing is symmetric with a hump in the middle. The higher either one gets, the more extreme the hump (meaning that value is far more common than any other). With a little fiddling, you can get a number of interesting curves.

Screenshots don’t really do it justice, so here’s a little Wolfram widget that lets you play with α and β live:

Note that if α = 1, then 1 is a possible value; if β = 1, then 0 is a possible value. You probably want them both greater than 1, which clamps the endpoints to zero.

Also, it’s possible to have either α or β or both be less than 1, but this creates very different behavior: the corresponding endpoints become poles.

Anyway, something like α = β = 3 is probably close enough to normal for most purposes but already clamped for you. And you could easily replicate something like, say, NetHack’s incredibly bizarre rnz function.

Random frequency

Say you want some event to have an 80% chance to happen every second. You (who am I kidding, I) might be tempted to do something like this:

if random() < 0.8 * dt:

In an ideal world, dt is always the same and is equal to 1 / f, where f is the framerate. Replace that 80% with a variable, say P, and every tic you have a P / f chance to do the… whatever it is.

Each second, f tics pass, so you’ll make this check f times. The chance that any check succeeds is the inverse of the chance that every check fails, which is \(1 – \left(1 – \frac{P}{f}\right)^f\).

For P of 80% and a framerate of 60, that’s a total probability of 55.3%. Wait, what?

Consider what happens if the framerate is 2. On the first tic, you roll 0.4 twice — but probabilities are combined by multiplying, and splitting work up by dt only works for additive quantities. You lose some accuracy along the way. If you’re dealing with something that multiplies, you need an exponent somewhere.

But in this case, maybe you don’t want that at all. Each separate roll you make might independently succeed, so it’s possible (but very unlikely) that the event will happen 60 times within a single second! Or 200 times, if that’s someone’s framerate.

If you explicitly want something to have a chance to happen on a specific interval, you have to check on that interval. If you don’t have a gizmo handy to run code on an interval, it’s easy to do yourself with a time buffer:

timer += dt
# here, 1 is the "every 1 seconds"
while timer > 1:
    timer -= 1
    if random() < 0.8:

Using while means rolls still happen even if you somehow skipped over an entire second.

(For the curious, and the nerds who already noticed: the expression \(1 – \left(1 – \frac{P}{f}\right)^f\) converges to a specific value! As the framerate increases, it becomes a better and better approximation for \(1 – e^{-P}\), which for the example above is 0.551. Hey, 60 fps is pretty accurate — it’s just accurately representing something nowhere near what I wanted. Er, you wanted.)

Rolling your own

Of course, you can fuss with the classic [0, 1] uniform value however you want. If I want a bias towards zero, I’ll often just square it, or multiply two of them together. If I want a bias towards one, I’ll take a square root. If I want something like a Gaussian/normal distribution, but with clearly-defined endpoints, I might add together n rolls and divide by n. (The normal distribution is just what you get if you roll infinite dice and divide by infinity!)

It’d be nice to be able to understand exactly what this will do to the distribution. Unfortunately, that requires some calculus, which this post is too small to contain, and which I didn’t even know much about myself until I went down a deep rabbit hole while writing, and which in many cases is straight up impossible to express directly.

Here’s the non-calculus bit. A source of randomness is often graphed as a PDF — a probability density function. You’ve almost certainly seen a bell curve graphed, and that’s a PDF. They’re pretty nice, since they do exactly what they look like: they show the relative chance that any given value will pop out. On a bog standard bell curve, there’s a peak at zero, and of course zero is the most common result from a normal distribution.

(Okay, actually, since the results are continuous, it’s vanishingly unlikely that you’ll get exactly zero — but you’re much more likely to get a value near zero than near any other number.)

For the uniform distribution, which is what a classic rand() gives you, the PDF is just a straight horizontal line — every result is equally likely.

If there were a calculus bit, it would go here! Instead, we can cheat. Sometimes. Mathematica knows how to work with probability distributions in the abstract, and there’s a free web version you can use. For the example of squaring a uniform variable, try this out:

PDF[TransformedDistribution[u^2, u \[Distributed] UniformDistribution[{0, 1}]], u]

(The \[Distributed] is a funny tilde that doesn’t exist in Unicode, but which Mathematica uses as a first-class operator. Also, press shiftEnter to evaluate the line.)

This will tell you that the distribution is… \(\frac{1}{2\sqrt{u}}\). Weird! You can plot it:

Plot[%, {u, 0, 1}]

(The % refers to the result of the last thing you did, so if you want to try several of these, you can just do Plot[PDF[…], u] directly.)

The resulting graph shows that numbers around zero are, in fact, vastly — infinitely — more likely than anything else.

What about multiplying two together? I can’t figure out how to get Mathematica to understand this, but a great amount of digging revealed that the answer is -ln x, and from there you can plot them both on Wolfram Alpha. They’re similar, though squaring has a much better chance of giving you high numbers than multiplying two separate rolls — which makes some sense, since if either of two rolls is a low number, the product will be even lower.

What if you know the graph you want, and you want to figure out how to play with a uniform roll to get it? Good news! That’s a whole thing called inverse transform sampling. All you have to do is take an integral. Good luck!

This is all extremely ridiculous. New tactic: Just Simulate The Damn Thing. You already have the code; run it a million times, make a histogram, and tada, there’s your PDF. That’s one of the great things about computers! Brute-force numerical answers are easy to come by, so there’s no excuse for producing something like rnz. (Though, be sure your histogram has sufficiently narrow buckets — I tried plotting one for rnz once and the weird stuff on the left side didn’t show up at all!)

By the way, I learned something from futzing with Mathematica here! Taking the square root (to bias towards 1) gives a PDF that’s a straight diagonal line, nothing like the hyperbola you get from squaring (to bias towards 0). How do you get a straight line the other way? Surprise: \(1 – \sqrt{1 – u}\).

Okay, okay, here’s the actual math

I don’t claim to have a very firm grasp on this, but I had a hell of a time finding it written out clearly, so I might as well write it down as best I can. This was a great excuse to finally set up MathJax, too.

Say \(u(x)\) is the PDF of the original distribution and \(u\) is a representative number you plucked from that distribution. For the uniform distribution, \(u(x) = 1\). Or, more accurately,

u(x) = \begin{cases}
1 & \text{ if } 0 \le x \lt 1 \\
0 & \text{ otherwise }

Remember that \(x\) here is a possible outcome you want to know about, and the PDF tells you the relative probability that a roll will be near it. This PDF spits out 1 for every \(x\), meaning every number between 0 and 1 is equally likely to appear.

We want to do something to that PDF, which creates a new distribution, whose PDF we want to know. I’ll use my original example of \(f(u) = u^2\), which creates a new PDF \(v(x)\).

The trick is that we need to work in terms of the cumulative distribution function for \(u\). Where the PDF gives the relative chance that a roll will be (“near”) a specific value, the CDF gives the relative chance that a roll will be less than a specific value.

The conventions for this seem to be a bit fuzzy, and nobody bothers to explain which ones they’re using, which makes this all the more confusing to read about… but let’s write the CDF with a capital letter, so we have \(U(x)\). In this case, \(U(x) = x\), a straight 45° line (at least between 0 and 1). With the definition I gave, this should make sense. At some arbitrary point like 0.4, the value of the PDF is 1 (0.4 is just as likely as anything else), and the value of the CDF is 0.4 (you have a 40% chance of getting a number from 0 to 0.4).

Calculus ahoy: the PDF is the derivative of the CDF, which means it measures the slope of the CDF at any point. For \(U(x) = x\), the slope is always 1, and indeed \(u(x) = 1\). See, calculus is easy.

Okay, so, now we’re getting somewhere. What we want is the CDF of our new distribution, \(V(x)\). The CDF is defined as the probability that a roll \(v\) will be less than \(x\), so we can literally write:

$$V(x) = P(v \le x)$$

(This is why we have to work with CDFs, rather than PDFs — a PDF gives the chance that a roll will be “nearby,” whatever that means. A CDF is much more concrete.)

What is \(v\), exactly? We defined it ourselves; it’s the do something applied to a roll from the original distribution, or \(f(u)\).

$$V(x) = P\!\left(f(u) \le x\right)$$

Now the first tricky part: we have to solve that inequality for \(u\), which means we have to do something, backwards to \(x\).

$$V(x) = P\!\left(u \le f^{-1}(x)\right)$$

Almost there! We now have a probability that \(u\) is less than some value, and that’s the definition of a CDF!

$$V(x) = U\!\left(f^{-1}(x)\right)$$

Hooray! Now to turn these CDFs back into PDFs, all we need to do is differentiate both sides and use the chain rule. If you never took calculus, don’t worry too much about what that means!

$$v(x) = u\!\left(f^{-1}(x)\right)\left|\frac{d}{dx}f^{-1}(x)\right|$$

Wait! Where did that absolute value come from? It takes care of whether \(f(x)\) increases or decreases. It’s the least interesting part here by far, so, whatever.

There’s one more magical part here when using the uniform distribution — \(u(\dots)\) is always equal to 1, so that entire term disappears! (Note that this only works for a uniform distribution with a width of 1; PDFs are scaled so the entire area under them sums to 1, so if you had a rand() that could spit out a number between 0 and 2, the PDF would be \(u(x) = \frac{1}{2}\).)

$$v(x) = \left|\frac{d}{dx}f^{-1}(x)\right|$$

So for the specific case of modifying the output of rand(), all we have to do is invert, then differentiate. The inverse of \(f(u) = u^2\) is \(f^{-1}(x) = \sqrt{x}\) (no need for a ± since we’re only dealing with positive numbers), and differentiating that gives \(v(x) = \frac{1}{2\sqrt{x}}\). Done! This is also why square root comes out nicer; inverting it gives \(x^2\), and differentiating that gives \(2x\), a straight line.

Incidentally, that method for turning a uniform distribution into any distribution — inverse transform sampling — is pretty much the same thing in reverse: integrate, then invert. For example, when I saw that taking the square root gave \(v(x) = 2x\), I naturally wondered how to get a straight line going the other way, \(v(x) = 2 – 2x\). Integrating that gives \(2x – x^2\), and then you can use the quadratic formula (or just ask Wolfram Alpha) to solve \(2x – x^2 = u\) for \(x\) and get \(f(u) = 1 – \sqrt{1 – u}\).

Multiply two rolls is a bit more complicated; you have to write out the CDF as an integral and you end up doing a double integral and wow it’s a mess. The only thing I’ve retained is that you do a division somewhere, which then gets integrated, and that’s why it ends up as \(-\ln x\).

And that’s quite enough of that! (Okay but having math in my blog is pretty cool and I will definitely be doing more of this, sorry, not sorry.)

Random vs varied

Sometimes, random isn’t actually what you want. We tend to use the word “random” casually to mean something more like chaotic, i.e., with no discernible pattern. But that’s not really random. In fact, given how good humans can be at finding incidental patterns, they aren’t all that unlikely! Consider that when you roll two dice, they’ll come up either the same or only one apart almost half the time. Coincidence? Well, yes.

If you ask for randomness, you’re saying that any outcome — or series of outcomes — is acceptable, including five heads in a row or five tails in a row. Most of the time, that’s fine. Some of the time, it’s less fine, and what you really want is variety. Here are a couple examples and some fairly easy workarounds.

NPC quips

The nature of games is such that NPCs will eventually run out of things to say, at which point further conversation will give the player a short brush-off quip — a slight nod from the designer to the player that, hey, you hit the end of the script.

Some NPCs have multiple possible quips and will give one at random. The trouble with this is that it’s very possible for an NPC to repeat the same quip several times in a row before abruptly switching to another one. With only a few options to choose from, getting the same option twice or thrice (especially across an entire game, which may have numerous NPCs) isn’t all that unlikely. The notion of an NPC quip isn’t very realistic to start with, but having someone repeat themselves and then abruptly switch to something else is especially jarring.

The easy fix is to show the quips in order! Paradoxically, this is more consistently varied than choosing at random — the original “order” is likely to be meaningless anyway, and it already has the property that the same quip can never appear twice in a row.

If you like, you can shuffle the list of quips every time you reach the end, but take care here — it’s possible that the last quip in the old order will be the same as the first quip in the new order, so you may still get a repeat. (Of course, you can just check for this case and swap the first quip somewhere else if it bothers you.)

That last behavior is, in fact, the canonical way that Tetris chooses pieces — the game simply shuffles a list of all 7 pieces, gives those to you in shuffled order, then shuffles them again to make a new list once it’s exhausted. There’s no avoidance of duplicates, though, so you can still get two S blocks in a row, or even two S and two Z all clumped together, but no more than that. Some Tetris variants take other approaches, such as actively avoiding repeats even several pieces apart or deliberately giving you the worst piece possible.

Random drops

Random drops are often implemented as a flat chance each time. Maybe enemies have a 5% chance to drop health when they die. Legally speaking, over the long term, a player will see health drops for about 5% of enemy kills.

Over the short term, they may be desperate for health and not survive to see the long term. So you may want to put a thumb on the scale sometimes. Games in the Metroid series, for example, have a somewhat infamous bias towards whatever kind of drop they think you need — health if your health is low, missiles if your missiles are low.

I can’t give you an exact approach to use, since it depends on the game and the feeling you’re going for and the variables at your disposal. In extreme cases, you might want to guarantee a health drop from a tough enemy when the player is critically low on health. (Or if you’re feeling particularly evil, you could go the other way and deny the player health when they most need it…)

The problem becomes a little different, and worse, when the event that triggers the drop is relatively rare. The pathological case here would be something like a raid boss in World of Warcraft, which requires hours of effort from a coordinated group of people to defeat, and which has some tiny chance of dropping a good item that will go to only one of those people. This is why I stopped playing World of Warcraft at 60.

Dialing it back a little bit gives us Enter the Gungeon, a roguelike where each room is a set of encounters and each floor only has a dozen or so rooms. Initially, you have a 1% chance of getting a reward after completing a room — but every time you complete a room and don’t get a reward, the chance increases by 9%, up to a cap of 80%. Once you get a reward, the chance resets to 1%.

The natural question is: how frequently, exactly, can a player expect to get a reward? We could do math, or we could Just Simulate The Damn Thing.

from collections import Counter
import random

histogram = Counter()

TRIALS = 1000000
chance = 1
rooms_cleared = 0
rewards_found = 0
while rewards_found < TRIALS:
    rooms_cleared += 1
    if random.random() * 100 < chance:
        # Reward!
        rewards_found += 1
        histogram[rooms_cleared] += 1
        rooms_cleared = 0
        chance = 1
        chance = min(80, chance + 9)

for gaps, count in sorted(histogram.items()):
    print(f"{gaps:3d} | {count / TRIALS * 100:6.2f}%", '#' * (count // (TRIALS // 100)))
  1 |   0.98%
  2 |   9.91% #########
  3 |  17.00% ################
  4 |  20.23% ####################
  5 |  19.21% ###################
  6 |  15.05% ###############
  7 |   9.69% #########
  8 |   5.07% #####
  9 |   2.09% ##
 10 |   0.63%
 11 |   0.12%
 12 |   0.03%
 13 |   0.00%
 14 |   0.00%
 15 |   0.00%

We’ve got kind of a hilly distribution, skewed to the left, which is up in this histogram. Most of the time, a player should see a reward every three to six rooms, which is maybe twice per floor. It’s vanishingly unlikely to go through a dozen rooms without ever seeing a reward, so a player should see at least one per floor.

Of course, this simulated a single continuous playthrough; when starting the game from scratch, your chance at a reward always starts fresh at 1%, the worst it can be. If you want to know about how many rewards a player will get on the first floor, hey, Just Simulate The Damn Thing.

  0 |   0.01%
  1 |  13.01% #############
  2 |  56.28% ########################################################
  3 |  27.49% ###########################
  4 |   3.10% ###
  5 |   0.11%
  6 |   0.00%

Cool. Though, that’s assuming exactly 12 rooms; it might be worth changing that to pick at random in a way that matches the level generator.

(Enter the Gungeon does some other things to skew probability, which is very nice in a roguelike where blind luck can make or break you. For example, if you kill a boss without having gotten a new gun anywhere else on the floor, the boss is guaranteed to drop a gun.)

Critical hits

I suppose this is the same problem as random drops, but backwards.

Say you have a battle sim where every attack has a 6% chance to land a devastating critical hit. Presumably the same rules apply to both the player and the AI opponents.

Consider, then, that the AI opponents have exactly the same 6% chance to ruin the player’s day. Consider also that this gives them an 0.4% chance to critical hit twice in a row. 0.4% doesn’t sound like much, but across an entire playthrough, it’s not unlikely that a player might see it happen and find it incredibly annoying.

Perhaps it would be worthwhile to explicitly forbid AI opponents from getting consecutive critical hits.

In conclusion

An emerging theme here has been to Just Simulate The Damn Thing. So consider Just Simulating The Damn Thing. Even a simple change to a random value can do surprising things to the resulting distribution, so unless you feel like differentiating the inverse function of your code, maybe test out any non-trivial behavior and make sure it’s what you wanted. Probability is hard to reason about.

PS4 4.05 Kernel Exploit Released, Full Jailbreak Round the Corner

Post Syndicated from Andy original https://torrentfreak.com/ps4-4-05-kernel-exploit-released-full-jailbreak-round-the-corner-171227/

Most custom hardware is seriously locked down these days, with many corporations viewing any tinkering with their machines as unacceptable at best, illegal at worst.

When people free computing hardware – so-called jailbreaking – it can be used for almost any purpose. The famous Cydia, for example, created a whole alternative iOS app store, one free of the constraints of Apple.

Of course, jailbreaking has also become synonymous with breaking fundamental copy protection, allowing pirated software to run on a range of devices from cellphones to today’s cutting-edge games consoles. The flip side of that coin is that people are also able to run so-called ‘homebrew’ code, programs developed by hobbyists for purposes that do not breach copyright law.

This ‘dual use’ situation means that two separate sets of communities get excited when exploits are found for key hardware. That’s been the case for some time now with two sets of developers – Team Fail0verflow and Specter – revealing work on a kernel exploit for firmware 4.05 on Playstation 4.

In November, Wololo published an interview with Specter and two days ago received direct confirmation that the exploit would be published soon. That moment has now arrived.

As noted in Specter’s tweet, the release is available on Github, where the developer provides more details.

“In this project you will find a full implementation of the ‘namedobj’ kernel exploit for the PlayStation 4 on 4.05,” Specter writes.

“It will allow you to run arbitrary code as kernel, to allow jailbreaking and kernel-level modifications to the system.”

The news that the exploit can enable a jailbreak is huge news for fans of the scene, who will be eagerly standing by for the next piece of the puzzle which is likely to be just around the corner.

Still, Specter is wisely exercising caution when it comes to the more risky side of his exploit – the potential for running homebrew and, of course, pirate games. He doesn’t personally include code for directly helping either.

“This release however, does not contain any code related to defeating anti-piracy mechanisms or running homebrew,” he notes.

That being said, the exploit clearly has potential and Specter has opened up a direct channel for those wishing to take things to the next level. He reveals that the exploit contains a loader that listens for a payload and once it receives it, executes it automatically.

“I’ve also uploaded a test payload you can use after the kernel exploit runs that jailbreaks and patches the kernel to allow access to debug settings, just needs to be netcatted to the loader via port 9020,” he concludes.

That’s likely to prove very attractive to those with a penchant for tinkering. Let’s see which direction this goes.

Source: TF, for the latest info on copyright, file-sharing, torrent sites and more. We also have VPN discounts, offers and coupons

Swedish Data Authority Investigates Piracy Settlement Letters

Post Syndicated from Andy original https://torrentfreak.com/swedish-data-authority-investigates-piracy-settlement-letters-171115/

Companies that aim to turn piracy into profit have been in existence for more than a decade but still the controversy around their practices continues.

Most, known colloquially as ‘copyright trolls’, monitor peer-to-peer networks such as BitTorrent, collecting IP addresses and other data in order to home in on a particular Internet account. From there, ISPs are sued to hand over that particular subscriber’s personal details. Once they’re obtained, the pressure begins.

At this point, trolls are in direct contact with the public, usually by letter. Their tone is almost always semi-aggressive, warning account holders that their actions are undermining entire industries. However, as if by magic, all the harm can be undone if they pay up few hundred dollars, euros, or pounds – quickly.

That’s the case in Sweden, where law firm Njord Law is representing the well-known international copyright trolls behind the movies CELL, IT, London Has Fallen, Mechanic: Resurrection, Criminal, and September of Shiraz.

“Have you, or other people with access to the aforementioned IP address, such as children living at home, viewed or tried to watch [a pirate movie] at the specified time?” Njord Law now writes in its letters to alleged pirates.

“If so, the case can be terminated by paying 4,500 SEK [$550].”

It’s clear that the companies involved are diving directly for cash. Indeed, letter recipients are told they have just two weeks to pay up or face further issues. The big question now is whether these demands are permissible under law, not necessarily from a copyright angle but due to the way they are presented to the alleged pirates.

The Swedish Data Protection Authority (Datainspektionen) is a public authority tasked with protecting the privacy of the individual in the information society. Swedish Radio reports that it has received several complaints from Swedes who have received cash demands and as a result is investigating whether the letters are legal.

As a result, the authority now has to determine whether the letters can be regarded as a debt collection measure. If so, they will have to comply with special laws and would also require special permission.

“They have not classified this as a debt collection fee, but it is not that element that is crucial. A debt collection measure is determined by whether there is any kind of pressure on the recipient to make a payment. Then there is the question of whether such pressure can be considered a debt collection measure,” says lawyer Camilla Sparr.

Of course, the notion that the letters exist for the purposes of collecting a debt is rejected by Njord Law. Lawyer Jeppe Brogaard Clausen says that his company has had no problems in this respect in other jurisdictions.

“We have encountered the same issue in Denmark and Finland and it was judged by the authorities that there is no talk about a debt collection letter,” Clausen told SR.

A lot hinges on the investigation of the Data Protection Authority. Njord Law has already obtained permission to find out the identities behind tens of thousands of IP addresses, including a single batch where 25,000 customers of ISP Telia were targeted.

At least 5,000 letters demanding payment have been sent out already and another 5,000 are lined up for the next few months. Clausen says their purpose is to change Swedes’ attitude towards illegal file sharing but there’s a broad belief that they’re part of a global network of companies whose aims are to generate profit from piracy.

But while the Data Protection Authority does its work, there is plenty of advice for letter recipients who don’t want to cave into demands for cash. Last month, Copyright Professor Sanna Wolk advised them to ignore the letters entirely.

“Do not pay. You do not even have to answer it,” Wolk told people receiving a letter.

“In the end, it’s the court that will decide whether you have to pay or not. We have seen this type of letter in the past, and only very few times those in charge of the claims have taken it to court.”

Of course, should copyright holders actually take a matter to court, then recipients must contest the claim since failure to do so could result in a default judgment. This means they lose the case without even having had the opportunity to mount a defense.

Importantly, one such defense could be that the individual didn’t carry out the offense, perhaps because their WiFi isn’t password protected or that they share their account with others.

“Someone who has an open network cannot be held responsible for copyright violations – such as downloading movies – if they provide others with access to their internet connection. This has been decided in a European Court ruling last year,” Wolk noted.

Source: TF, for the latest info on copyright, file-sharing, torrent sites and more. We also have VPN discounts, offers and coupons

Assassins Creed Origin DRM Hammers Gamers’ CPUs

Post Syndicated from Andy original https://torrentfreak.com/assassins-creed-origin-drm-hammers-gamers-cpus-171030/

There’s a war taking place on the Internet. On one side: gaming companies, publishers, and anti-piracy outfits. On the other: people who varying reasons want to play and/or test games for free.

While these groups are free to battle it out in a manner of their choosing, innocent victims are getting caught up in the crossfire. People who pay for their games without question should be considered part of the solution, not the problem, but whether they like it or not, they’re becoming collateral damage in an increasingly desperate conflict.

For the past several days, some players of the recently-released Assassin’s Creed Origins have emerged as what appear to be examples of this phenomenon.

“What is the normal CPU usage for this game?” a user asked on Steam forums. “I randomly get between 60% to 90% and I’m wondering if this is too high or not.”

The individual reported running an i7 processor, which is no slouch. However, for those running a CPU with less oomph, matters are even worse. Another gamer, running an i5, reported a 100% load on all four cores of his processor, even when lower graphics settings were selected in an effort to free up resources.

“It really doesn’t seem to matter what kind of GPU you are using,” another complained. “The performance issues most people here are complaining about are tied to CPU getting maxed out 100 percent at all times. This results in FPS [frames per second] drops and stutter. As far as I know there is no workaround.”

So what could be causing these problems? Badly configured machines? Terrible coding on the part of the game maker?

According to Voksi, whose ‘Revolt’ team cracked Wolfenstein II: The New Colossus before its commercial release last week, it’s none of these. The entire problem is directly connected to desperate anti-piracy measures.

As widely reported (1,2), the infamous Denuvo anti-piracy technology has been taking a beating lately. Cracking groups are dismantling it in a matter of days, sometimes just hours, making the protection almost pointless. For Assassin’s Creed Origins, however, Ubisoft decided to double up, Voksi says.

“Basically, Ubisoft have implemented VMProtect on top of Denuvo, tanking the game’s performance by 30-40%, demanding that people have a more expensive CPU to play the game properly, only because of the DRM. It’s anti-consumer and a disgusting move,” he told TorrentFreak.

Voksi says he knows all of this because he got an opportunity to review the code after obtaining the binaries for the game. Here’s how it works.

While Denuvo sits underneath doing its thing, it’s clearly vulnerable to piracy, given recent advances in anti-anti-piracy technology. So, in a belt-and-braces approach, Ubisoft opted to deploy another technology – VMProtect – on top.

VMProtect is software that protects other software against reverse engineering and cracking. Although the technicalities are different, its aims appear to be somewhat similar to Denuvo, in that both seek to protect underlying systems from being subverted.

“VMProtect protects code by executing it on a virtual machine with non-standard architecture that makes it extremely difficult to analyze and crack the software. Besides that, VMProtect generates and verifies serial numbers, limits free upgrades and much more,” the company’s marketing reads.

VMProtect and Denuvo didn’t appear to be getting on all that well earlier this year but they later settled their differences. Now their systems are working together, to try and solve the anti-piracy puzzle.

“It seems that Ubisoft decided that Denuvo is not enough to stop pirates in the crucial first days [after release] anymore, so they have implemented an iteration of VMProtect over it,” Voksi explains.

“This is great if you are looking to save your game from those pirates, because this layer of VMProtect will make Denuvo a lot more harder to trace and keygen than without it. But if you are a legit customer, well, it’s not that great for you since this combo could tank your performance by a lot, especially if you are using a low-mid range CPU. That’s why we are seeing 100% CPU usage on 4 core CPUs right now for example.”

The situation is reportedly so bad that some users are getting the dreaded BSOD (blue screen of death) due to their machines overheating after just an hour or two’s play. It remains unclear whether these crashes are indeed due to the VMProtect/Denuvo combination but the perception is that these anti-piracy measures are at the root of users’ CPU utilization problems.

While gaming companies can’t be blamed for wanting to protect their products, there’s no sense in punishing legitimate consumers with an inferior experience. The great irony, of course, is that when Assassin’s Creed gets cracked (if that indeed happens anytime soon), pirates will be the only ones playing it without the hindrance of two lots of anti-piracy tech battling over resources.

The big question now, however, is whether the anti-piracy wall will stand firm. If it does, it raises the bizarre proposition that future gamers might need to buy better hardware in order to accommodate anti-piracy technology.

And people worry about bitcoin mining……?

Source: TF, for the latest info on copyright, file-sharing, torrent sites and ANONYMOUS VPN services.

Copyright Professor: Don’t Pay Those File-Sharing ‘Fines’

Post Syndicated from Ernesto original https://torrentfreak.com/copyright-professor-dont-pay-those-file-sharing-fines-171027/

In recent years, file-sharers around the world have been pressured to pay significant settlement fees, or face legal repercussions.

Sweden is not spared from these practices. A recent wave of threatening letters, sent out on behalf of film distributors including those behind the zombie movie Cell, targets thousands of local Internet users.

The campaign is coordinated by Danish law firm Njord Law. The company accuses people of downloading the movie without permission and demands a settlement, as is common with these copyright troll schemes.

The scope of the latest campaign is enormous as 20,000 new IP-addresses were collected. Swedish courts can order ISPs to uncover the identities of thousands of IP addresses, in a single batch. That’s quite a lot compared to the US, where the same filmmakers can target only a dozen Internet accounts at a time.

While recipients of these letters can be easily scared by the legal language and proposed 4,500 SEK [$550] settlement, not all experts are impressed.

Sanna Wolk, Intellectual Property Professor at Uppsala University, recommends people to ignore the letters entirely.

“Do not pay. You do not even have to answer it. In the end, it’s the court that will decide whether you have to pay or not. We have seen this type of letter in the past, and only very few times those in charge of the claims have taken it to court,” Wolk tells Ny Teknik.

However, if the case does indeed move beyond a threat and goes to court then it’s important for the accused to contest the claim.

Njord Law says that it will follow up on their ‘promise’ and take people to court if they ignore their settlement requests.

Whether they have the resources to sue thousands of people is questionable though. Similarly, it remains to be seen how good an IP-address is as evidence, since it doesn’t identify a single person, just a connection.

The law firm also highlights that subscribers can be held liable even if someone else used their connection to download the film. However, professor Wolk stresses that this isn’t necessarily true.

“Someone who has an open network cannot be held responsible for copyright violations – such as downloading movies – if they provide others with access to their internet connection. This has been decided in a European Court ruling last year,” she states.

The Copyright Professor refers to the McFadden vs Sony Music ruling where the EU Court of Justice found that the operator of an open WiFi network can’t be held liable for infringements carried out by his users.

National courts have some leeway and could order someone to protect his or her WiFi connection, but this doesn’t mean that they are liable for past infringements.

It’s doubtful that Njord Law and their clients will change their tune. Not all people will read the professor’s comments and their scheme generally thrives on the easily threatened and uninformed. Still, most of the accused will probably sleep better after reading it.

Source: TF, for the latest info on copyright, file-sharing, torrent sites and ANONYMOUS VPN services.

[$] Safety-critical realtime with Linux

Post Syndicated from corbet original https://lwn.net/Articles/734694/rss

Doing realtime processing with a general-purpose operating-system like
Linux can be a challenge by itself, but safety-critical realtime processing
ups the ante considerably. During a session at Open Source Summit North
America, Wolfgang Maurer discussed the difficulties involved in this kind
of work and what Linux has to offer.

FRED-209 Nerf gun tank

Post Syndicated from Janina Ander original https://www.raspberrypi.org/blog/nerf-gun-tank-fred-209/

David Pride, known to many of you as an active member of our maker community, has done it again! His FRED-209 build combines a Nerf gun, 3D printing, a Raspberry Pi Zero, and robotics to make one neat remotely controlled Nerf tank.

FRED-209 – 3D printed Raspberry Pi Nerf Tank

Uploaded by David Pride on 2017-09-17.

A Nerf gun for FRED-209

David says he worked on FRED-209 over the summer in order to have some fun with Nerf guns, which weren’t around when he was a kid. He purchased an Elite Stryfe model at a car boot sale, and took it apart to see what made it tick. Then he set about figuring out how to power it with motors and a servo.

Nerf Elite Stryfe components for the FRED-209 Nerf tank of David Pride

To control the motors, David used a ZeroBorg add-on board for the Pi Zero, and he set up a PlayStation 3 controller to pilot his tank. These components were also part of a robot that David entered into the Pi Wars competition, so he had already written code for them.

3D printing for FRED-209

During prototyping for his Nerf tank, which David named after ED-209 from RoboCop, he used lots of eBay loot and several 3D-printed parts. He used the free OpenSCAD software package to design the parts he wanted to print. If you’re a novice at 3D printing, you might find the printing advice he shares in the write-up on his blog very useful.

3D-printed lid of FRED-209 nerf gun tank by David Pride

David found the 3D printing of the 24cm-long lid of FRED-209 tricky

On eBay, David found some cool-looking chunky wheels, but these turned out to be too heavy for the motors. In the end, he decided to use a Rover 5 chassis, which changed the look of FRED-209 from ‘monster truck’ to ‘tank’.

FRED-209 Nerf tank by David Pride

Next step: teach it to use stairs

The final result looks awesome, and David’s video demonstrates that it shoots very accurately as well. A make like this might be a great defensive project for our new apocalypse-themed Pioneers challenge!

Taking FRED-209 further

David will be uploading code and STL files for FRED-209 soon, so keep an eye on his blog or Twitter for updates. He’s also bringing the Nerf tank to the Cotswold Raspberry Jam this weekend. If you’re attending the event, make sure you catch him and try FRED-209 out yourself.

Never one to rest on his laurels, David is already working on taking his build to the next level. He wants to include a web interface controller and a camera, and is working on implementing OpenCV to give the Nerf tank the ability to autonomously detect targets.

Pi Wars 2018

I have a feeling we might get to see an advanced version of David’s project at next year’s Pi Wars!

The 2018 Pi Wars have just been announced. They will take place on 21-22 April at the Cambridge Computer Laboratory, and you have until 3 October to apply to enter the competition. What are you waiting for? Get making! And as always, do share your robot builds with us via social media.

The post FRED-209 Nerf gun tank appeared first on Raspberry Pi.

Kim Dotcom Spying Fiasco Puts Prime Minister Under Pressure

Post Syndicated from Andy original https://torrentfreak.com/kim-dotcom-spying-fiasco-puts-prime-minister-under-pressure-170725/

In the lead up to the January 2012 raid on cloud storage site Megaupload, authorities in New Zealand used the Government Communications Security Bureau (GCSB) agency to spy on Kim and Mona Dotcom, plus Megaupload co-defendant Bram van der Kolk. That should not have happened.

Intelligence agency GCSB was forbidden by law from conducting surveillance on its own citizens or permanent residents in the country. Former Prime Minister John Key later apologized for the glaring error but for Dotcom, that wasn’t enough. The entrepreneur launched legal action in pursuit of the information illegally obtained by GCSB and appropriate compensation.

Last week the High Court decided that Dotcom wouldn’t get access to the information but it also revealed something of much interest. Instead of confirming that the illegal spying on Dotcom took place December 16, 2011, through to January 20, 2012, the range was extended by two months to March 22, 2012.

The implications of the extension are numerous, not least that GCSB continued to spy on Dotcom even after it knew it was acting illegally. The reveal also undermines an earlier affidavit from a GCSB staff member, problems which are now returning to haunt New Zealand Prime Minister, Bill English.

When the spying was taking place, John Key was Prime Minister but when Key traveled overseas, English was left at the helm. As a result, when the possibility that Dotcom had been spied on was raised during court hearings in 2012, it was English who was approached by the GCSB with a request to have its involvement made a state secret.

According to NZHerald, English was briefed by then-GCSB director Ian Fletcher and former acting director Hugh Wolfensohn on GCSB’s assistance to the police in the Dotcom case.

The content of those discussion has not been made public but English appears to have been convinced of the need to keep the information private. He subsequently signed a ministerial certificate, which barred disclosure of GCSB activities, even by people asked to provide them in a court of law.

However, since GCSB had broken the law by illegally spying on the Dotcoms and van Der Kolk, the certificate subsequently collapsed. But, like a dog with a bone, Dotcom isn’t letting this go, claiming that acting Prime Minister English acted unlawfully by signing the certificate in an effort to suppress wrong-doing.

“The ministerial certificate was an attempted cover-up. Bill English must have been briefed that GCSB was facing legal troubles because of unlawful conduct,” he told NZHerald.

“And only after the attempted gag-order failed in the High Court did the Government admit unlawful spying with a fake narrative that it was all a big mistake, a misunderstanding of the law, an error.”

Following the judgment last week that revealed the extended spying period, Dotcom confirms that there will be fresh legal action to obtain information from GCSB.

“The new revelations completely undermine the government narrative and it raises new questions about what really happened,” Dotcom concludes.

Source: TF, for the latest info on copyright, file-sharing, torrent sites and ANONYMOUS VPN services.

Teaching with Raspberry Pis and PiNet

Post Syndicated from Janina Ander original https://www.raspberrypi.org/blog/teaching-pinet/

Education is our mission at the Raspberry Pi Foundation, so of course we love tools that help teachers and other educators use Raspberry Pis in a classroom setting. PiNet, which allows teachers to centrally manage a whole classroom’s worth of Pis, makes administrating a fleet of Pis easier. Set up individual student accounts, install updates and software, share files – PiNet helps you do all of this!

Caleb VinCross on Twitter

The new PiNet lab up and running. 30 raspberry pi 3’s running as fat clients for 600 + students. Much thanks to the PiNet team! @PiNetDev.

PiNet developer Andrew

PiNet was built and is maintained by Andrew Mulholland, who started work on this project when he was 15, and who is also one of the organisers of the Northern Ireland Raspberry Jam. Check out what he says about PiNet’s capabilities in his guest post here.

PiNet in class

PiNet running in a classroom

PiNet, teacher’s pet

PiNet has been available for about two years now, and the teachers using it are over the moon. Here’s what a few of them say about their experience:

We wanted a permanently set up classroom with 30+ Raspberry Pis to teach programming. Students wanted their work to be secure and backed up and we needed a way to keep the Pis up to date. PiNet has made both possible and the classroom now required little or no maintenance. PiNet was set up in a single day and was so successful we set up a second Pi room. We now have 60 Raspberry Pis which are used by our students every day. – Rob Jones, Secondary School Teacher, United Kingdom

AKS Computing on Twitter

21xRaspPi+dedicated network+PiNet server+3 geeks = success! Ready to test with a full class.

I teach Computer Science at middle school, so I have 4 classes per day in my lab, sharing 20 Raspberry Pis. PiNet gives each student separate storage space. Any changes to the Raspbian image can be done from my dashboard. We use Scratch, Minecraft Pi, Sonic Pi, and do physical computing. And when I have had issues, or have wanted to try something a little crazy, the support has been fabulous. – Bob Irving, Middle School Teacher, USA

Wolf Math on Twitter

We’re starting our music unit with @deejaydoc. My CS students are going through the @Sonic_Pi turorial on @PiNetDev.

I teach computer classes for about 600 students between the ages of 5 and 13. PiNet has really made it possible to expand our technology curriculum beyond the simple web-based applications that our Chromebooks were limited to. I’m now able to use Arduino boards to do basic physical computing with LEDs and sensors. None of this could have happened without PiNet making it easy to have an affordable, stable, and maintainable way of managing 30 Linux computers in our lab. – Caleb VinCross, Primary School Teacher, USA

More for educators

If you’re involved in teaching computing, be that as a professional or as a volunteer, check out the new free magazine Hello World, brought to you by Computing At School, BCS Academy of Computing, and Raspberry Pi working in partnership. It is written by educators for educators, and available in print and as a PDF download. And if you’d like to keep up to date with what we are offering to educators and learners, sign up for our education newsletter here.

Are you a teacher who uses Raspberry Pis in the classroom, or another kind of educator who has used them in a group setting? Tell us about your experience in the comments below.

The post Teaching with Raspberry Pis and PiNet appeared first on Raspberry Pi.

Three Men Sentenced Following £2.5m Internet Piracy Case

Post Syndicated from Andy original https://torrentfreak.com/three-men-sentenced-following-2-5m-internet-piracy-case-170622/

While legal action against low-level individual file-sharers is extremely rare in the UK, the country continues to pose a risk for those engaged in larger-scale infringement.

That is largely due to the activities of the Police Intellectual Property Crime Unit and private anti-piracy outfits such as the Federation Against Copyright Theft (FACT). Investigations are often a joint effort which can take many years to complete, but the outcomes can often involve criminal sentences.

That was the profile of another Internet piracy case that concluded in London this week. It involved three men from the UK, Eric Brooks, 43, from Bolton, Mark Valentine, 44, from Manchester, and Craig Lloyd, 33, from Wolverhampton.

The case began when FACT became aware of potentially infringing activity back in February 2011. The anti-piracy group then investigated for more than a year before handing the case to police in March 2012.

On July 4, 2012, officers from City of London Police arrested Eric Brooks’ at his home in Bolton following a joint raid with FACT. Computer equipment was seized containing evidence that Brooks had been running a Netherlands-based server hosting more than £100,000 worth of pirated films, music, games, software and ebooks.

According to police, a spreadsheet on Brooks’ computer revealed he had hundreds of paying customers, all recruited from online forums. Using PayPal or utilizing bank transfers, each paid money to access the server. Police mentioned no group or site names in information released this week.

“Enquiries with PayPal later revealed that [Brooks] had made in excess of £500,000 in the last eight years from his criminal business and had in turn defrauded the film and TV industry alone of more than £2.5 million,” police said.

“As his criminal enterprise affected not only the film and TV but the wider entertainment industry including music, games, books and software it is thought that he cost the wider industry an amount much higher than £2.5 million.”

On the same day police arrested Brooks, Mark Valentine’s home in Manchester had a similar unwelcome visit. A day later, Craig Lloyd’s home in Wolverhampton become the third target for police.

Computer equipment was seized from both addresses which revealed that the pair had been paying for access to Brooks’ servers in order to service their own customers.

“They too had used PayPal as a means of taking payment and had earned thousands of pounds from their criminal actions; Valentine gaining £34,000 and Lloyd making over £70,000,” police revealed.

But after raiding the trio in 2012, it took more than four years to charge the men. In a feature common to many FACT cases, all three were charged with Conspiracy to Defraud rather than copyright infringement offenses. All three men pleaded guilty before trial.

On Monday, the men were sentenced at Inner London Crown Court. Brooks was sentenced to 24 months in prison, suspended for 12 months and ordered to complete 140 hours of unpaid work.

Valentine and Lloyd were each given 18 months in prison, suspended for 12 months. Each was ordered to complete 80 hours unpaid work.

Detective Constable Chris Glover, who led the investigation for the City of London Police, welcomed the sentencing.

“The success of this investigation is a result of co-ordinated joint working between the City of London Police and FACT. Brooks, Valentine and Lloyd all thought that they were operating under the radar and doing something which they thought was beyond the controls of law enforcement,” Glover said.

“Brooks, Valentine and Lloyd will now have time in prison to reflect on their actions and the result should act as deterrent for anyone else who is enticed by abusing the internet to the detriment of the entertainment industry.”

While even suspended sentences are a serious matter, none of the men will see the inside of a cell if they meet the conditions of their sentence for the next 12 months. For a case lasting four years involving such large sums of money, that is probably a disappointing result for FACT and the police.

Nevertheless, the men won’t be allowed to enjoy the financial proceeds of their piracy, if indeed any money is left. City of London Police say the trio will be subject to a future confiscation hearing to seize any proceeds of crime.

Source: TF, for the latest info on copyright, file-sharing, torrent sites and ANONYMOUS VPN services.

Building Loosely Coupled, Scalable, C# Applications with Amazon SQS and Amazon SNS

Post Syndicated from Tara Van Unen original https://aws.amazon.com/blogs/compute/building-loosely-coupled-scalable-c-applications-with-amazon-sqs-and-amazon-sns/

Stephen Liedig, Solutions Architect


One of the many challenges professional software architects and developers face is how to make cloud-native applications scalable, fault-tolerant, and highly available.

Fundamental to your project success is understanding the importance of making systems highly cohesive and loosely coupled. That means considering the multi-dimensional facets of system coupling to support the distributed nature of the applications that you are building for the cloud.

By that, I mean addressing not only the application-level coupling (managing incoming and outgoing dependencies), but also considering the impacts of of platform, spatial, and temporal coupling of your systems. Platform coupling relates to the interoperability, or lack thereof, of heterogeneous systems components. Spatial coupling deals with managing components at a network topology level or protocol level. Temporal, or runtime coupling, refers to the ability of a component within your system to do any kind of meaningful work while it is performing a synchronous, blocking operation.

The AWS messaging services, Amazon SQS and Amazon SNS, help you deal with these forms of coupling by providing mechanisms for:

  • Reliable, durable, and fault-tolerant delivery of messages between application components
  • Logical decomposition of systems and increased autonomy of components
  • Creating unidirectional, non-blocking operations, temporarily decoupling system components at runtime
  • Decreasing the dependencies that components have on each other through standard communication and network channels

Following on the recent topic, Building Scalable Applications and Microservices: Adding Messaging to Your Toolbox, in this post, I look at some of the ways you can introduce SQS and SNS into your architectures to decouple your components, and show how you can implement them using C#.


To illustrate some of these concepts, consider a web application that processes customer orders. As good architects and developers, you have followed best practices and made your application scalable and highly available. Your solution included implementing load balancing, dynamic scaling across multiple Availability Zones, and persisting orders in a Multi-AZ Amazon RDS database instance, as in the following diagram.

In this example, the application is responsible for handling and persisting the order data, as well as dealing with increases in traffic for popular items.

One potential point of vulnerability in the order processing workflow is in saving the order in the database. The business expects that every order has been persisted into the database. However, any potential deadlock, race condition, or network issue could cause the persistence of the order to fail. Then, the order is lost with no recourse to restore the order.

With good logging capability, you may be able to identify when an error occurred and which customer’s order failed. This wouldn’t allow you to “restore” the transaction, and by that stage, your customer is no longer your customer.

As illustrated in the following diagram, introducing an SQS queue helps improve your ordering application. Using the queue isolates the processing logic into its own component and runs it in a separate process from the web application. This, in turn, allows the system to be more resilient to spikes in traffic, while allowing work to be performed only as fast as necessary in order to manage costs.

In addition, you now have a mechanism for persisting orders as messages (with the queue acting as a temporary database), and have moved the scope of your transaction with your database further down the stack. In the event of an application exception or transaction failure, this ensures that the order processing can be retired or redirected to the Amazon SQS Dead Letter Queue (DLQ), for re-processing at a later stage. (See the recent post, Using Amazon SQS Dead-Letter Queues to Control Message Failure, for more information on dead-letter queues.)

Scaling the order processing nodes

This change allows you now to scale the web application frontend independently from the processing nodes. The frontend application can continue to scale based on metrics such as CPU usage, or the number of requests hitting the load balancer. Processing nodes can scale based on the number of orders in the queue. Here is an example of scale-in and scale-out alarms that you would associate with the scaling policy.

Scale-out Alarm

aws cloudwatch put-metric-alarm --alarm-name AddCapacityToCustomerOrderQueue --metric-name ApproximateNumberOfMessagesVisible --namespace "AWS/SQS" 
--statistic Average --period 300 --threshold 3 --comparison-operator GreaterThanOrEqualToThreshold --dimensions Name=QueueName,Value=customer-orders
--evaluation-periods 2 --alarm-actions <arn of the scale-out autoscaling policy>

Scale-in Alarm

aws cloudwatch put-metric-alarm --alarm-name RemoveCapacityFromCustomerOrderQueue --metric-name ApproximateNumberOfMessagesVisible --namespace "AWS/SQS" 
 --statistic Average --period 300 --threshold 1 --comparison-operator LessThanOrEqualToThreshold --dimensions Name=QueueName,Value=customer-orders
 --evaluation-periods 2 --alarm-actions <arn of the scale-in autoscaling policy>

In the above example, use the ApproximateNumberOfMessagesVisible metric to discover the queue length and drive the scaling policy of the Auto Scaling group. Another useful metric is ApproximateAgeOfOldestMessage, when applications have time-sensitive messages and developers need to ensure that messages are processed within a specific time period.

Scaling the order processing implementation

On top of scaling at an infrastructure level using Auto Scaling, make sure to take advantage of the processing power of your Amazon EC2 instances by using as many of the available threads as possible. There are several ways to implement this. In this post, we build a Windows service that uses the BackgroundWorker class to process the messages from the queue.

Here’s a closer look at the implementation. In the first section of the consuming application, use a loop to continually poll the queue for new messages, and construct a ReceiveMessageRequest variable.

public static void PollQueue()
    while (_running)
        Task<ReceiveMessageResponse> receiveMessageResponse;

        // Pull messages off the queue
        using (var sqs = new AmazonSQSClient())
            const int maxMessages = 10;  // 1-10

            //Receiving a message
            var receiveMessageRequest = new ReceiveMessageRequest
                // Get URL from Configuration
                QueueUrl = _queueUrl, 
                // The maximum number of messages to return. 
                // Fewer messages might be returned. 
                MaxNumberOfMessages = maxMessages, 
                // A list of attributes that need to be returned with message.
                AttributeNames = new List<string> { "All" },
                // Enable long polling. 
                // Time to wait for message to arrive on queue.
                WaitTimeSeconds = 5 

            receiveMessageResponse = sqs.ReceiveMessageAsync(receiveMessageRequest);

The WaitTimeSeconds property of the ReceiveMessageRequest specifies the duration (in seconds) that the call waits for a message to arrive in the queue before returning a response to the calling application. There are a few benefits to using long polling:

  • It reduces the number of empty responses by allowing SQS to wait until a message is available in the queue before sending a response.
  • It eliminates false empty responses by querying all (rather than a limited number) of the servers.
  • It returns messages as soon any message becomes available.

For more information, see Amazon SQS Long Polling.

After you have returned messages from the queue, you can start to process them by looping through each message in the response and invoking a new BackgroundWorker thread.

// Process messages
if (receiveMessageResponse.Result.Messages != null)
    foreach (var message in receiveMessageResponse.Result.Messages)
        Console.WriteLine("Received SQS message, starting worker thread");

        // Create background worker to process message
        BackgroundWorker worker = new BackgroundWorker();
        worker.DoWork += (obj, e) => ProcessMessage(message);
    Console.WriteLine("No messages on queue");

The event handler, ProcessMessage, is where you implement business logic for processing orders. It is important to have a good understanding of how long a typical transaction takes so you can set a message VisibilityTimeout that is long enough to complete your operation. If order processing takes longer than the specified timeout period, the message becomes visible on the queue. Other nodes may pick it and process the same order twice, leading to unintended consequences.

Handling Duplicate Messages

In order to manage duplicate messages, seek to make your processing application idempotent. In mathematics, idempotent describes a function that produces the same result if it is applied to itself:

f(x) = f(f(x))

No matter how many times you process the same message, the end result is the same (definition from Enterprise Integration Patterns: Designing, Building, and Deploying Messaging Solutions, Hohpe and Wolf, 2004).

There are several strategies you could apply to achieve this:

  • Create messages that have inherent idempotent characteristics. That is, they are non-transactional in nature and are unique at a specified point in time. Rather than saying “place new order for Customer A,” which adds a duplicate order to the customer, use “place order <orderid> on <timestamp> for Customer A,” which creates a single order no matter how often it is persisted.
  • Deliver your messages via an Amazon SQS FIFO queue, which provides the benefits of message sequencing, but also mechanisms for content-based deduplication. You can deduplicate using the MessageDeduplicationId property on the SendMessage request or by enabling content-based deduplication on the queue, which generates a hash for MessageDeduplicationId, based on the content of the message, not the attributes.
var sendMessageRequest = new SendMessageRequest
    QueueUrl = _queueUrl,
    MessageBody = JsonConvert.SerializeObject(order),
    MessageGroupId = Guid.NewGuid().ToString("N"),
    MessageDeduplicationId = Guid.NewGuid().ToString("N")
  • If using SQS FIFO queues is not an option, keep a message log of all messages attributes processed for a specified period of time, as an alternative to message deduplication on the receiving end. Verifying the existence of the message in the log before processing the message adds additional computational overhead to your processing. This can be minimized through low latency persistence solutions such as Amazon DynamoDB. Bear in mind that this solution is dependent on the successful, distributed transaction of the message and the message log.

Handling exceptions

Because of the distributed nature of SQS queues, it does not automatically delete the message. Therefore, you must explicitly delete the message from the queue after processing it, using the message ReceiptHandle property (see the following code example).

However, if at any stage you have an exception, avoid handling it as you normally would. The intention is to make sure that the message ends back on the queue, so that you can gracefully deal with intermittent failures. Instead, log the exception to capture diagnostic information, and swallow it.

By not explicitly deleting the message from the queue, you can take advantage of the VisibilityTimeout behavior described earlier. Gracefully handle the message processing failure and make the unprocessed message available to other nodes to process.

In the event that subsequent retries fail, SQS automatically moves the message to the configured DLQ after the configured number of receives has been reached. You can further investigate why the order process failed. Most importantly, the order has not been lost, and your customer is still your customer.

private static void ProcessMessage(Message message)
    using (var sqs = new AmazonSQSClient())
            Console.WriteLine("Processing message id: {0}", message.MessageId);

            // Implement messaging processing here
            // Ensure no downstream resource contention (parallel processing)
            // <your order processing logic in here…>
            Console.WriteLine("{0} Thread {1}: {2}", DateTime.Now.ToString("s"), Thread.CurrentThread.ManagedThreadId, message.MessageId);
            // Delete the message off the queue. 
            // Receipt handle is the identifier you must provide 
            // when deleting the message.
            var deleteRequest = new DeleteMessageRequest(_queueName, message.ReceiptHandle);
            Console.WriteLine("Processed message id: {0}", message.MessageId);

        catch (Exception ex)
            // Do nothing.
            // Swallow exception, message will return to the queue when 
            // visibility timeout has been exceeded.
            Console.WriteLine("Could not process message due to error. Exception: {0}", ex.Message);

Using SQS to adapt to changing business requirements

One of the benefits of introducing a message queue is that you can accommodate new business requirements without dramatically affecting your application.

If, for example, the business decided that all orders placed over $5000 are to be handled as a priority, you could introduce a new “priority order” queue. The way the orders are processed does not change. The only significant change to the processing application is to ensure that messages from the “priority order” queue are processed before the “standard order” queue.

The following diagram shows how this logic could be isolated in an “order dispatcher,” whose only purpose is to route order messages to the appropriate queue based on whether the order exceeds $5000. Nothing on the web application or the processing nodes changes other than the target queue to which the order is sent. The rates at which orders are processed can be achieved by modifying the poll rates and scalability settings that I have already discussed.

Extending the design pattern with Amazon SNS

Amazon SNS supports reliable publish-subscribe (pub-sub) scenarios and push notifications to known endpoints across a wide variety of protocols. It eliminates the need to periodically check or poll for new information and updates. SNS supports:

  • Reliable storage of messages for immediate or delayed processing
  • Publish / subscribe – direct, broadcast, targeted “push” messaging
  • Multiple subscriber protocols
  • Amazon SQS, HTTP, HTTPS, email, SMS, mobile push, AWS Lambda

With these capabilities, you can provide parallel asynchronous processing of orders in the system and extend it to support any number of different business use cases without affecting the production environment. This is commonly referred to as a “fanout” scenario.

Rather than your web application pushing orders to a queue for processing, send a notification via SNS. The SNS messages are sent to a topic and then replicated and pushed to multiple SQS queues and Lambda functions for processing.

As the diagram above shows, you have the development team consuming “live” data as they work on the next version of the processing application, or potentially using the messages to troubleshoot issues in production.

Marketing is consuming all order information, via a Lambda function that has subscribed to the SNS topic, inserting the records into an Amazon Redshift warehouse for analysis.

All of this, of course, is happening without affecting your order processing application.


While I haven’t dived deep into the specifics of each service, I have discussed how these services can be applied at an architectural level to build loosely coupled systems that facilitate multiple business use cases. I’ve also shown you how to use infrastructure and application-level scaling techniques, so you can get the most out of your EC2 instances.

One of the many benefits of using these managed services is how quickly and easily you can implement powerful messaging capabilities in your systems, and lower the capital and operational costs of managing your own messaging middleware.

Using Amazon SQS and Amazon SNS together can provide you with a powerful mechanism for decoupling application components. This should be part of design considerations as you architect for the cloud.

For more information, see the Amazon SQS Developer Guide and Amazon SNS Developer Guide. You’ll find tutorials on all the concepts covered in this post, and more. To can get started using the AWS console or SDK of your choice visit:

Happy messaging!

BackMap, the haptic navigation system

Post Syndicated from Janina Ander original https://www.raspberrypi.org/blog/backmap-haptic/

At this year’s TechCrunch Disrupt NY hackathon, one team presented BackMap, a haptic feedback system which helps visually impaired people to navigate cities and venues. It is assisted by a Raspberry Pi and integrated into a backpack.

Good vibrations with BackMap

The team, including Shashank Sharma, wrote an iOS phone app in Swift, Apple’s open-source programming language. To convert between addresses and geolocations, they used the Esri APIs offered by PubNub. So far, so standard. However, they then configured their BackMap setup so that the user can input their destination via the app, and then follow the route without having to look at a screen or listen to directions. Instead, vibrating motors have been integrated into the straps of a backpack and hooked up to a Raspberry Pi. Whenever the user needs to turn left or right, the Pi makes the respective motor vibrate.

Disrupt NY 2017 Hackathon | Part 1

Disrupt NY 2017 Hackathon presentations filmed live on May 15th, 2017. Preceding the Disrupt Conference is Hackathon weekend on May 13-14, where developers and engineers descend from all over the world to take part in a 24-hour hacking endurance test.

BackMap can also be adapted for indoor navigation by receiving signals from beacons. This could be used to direct users to toilet facilities or exhibition booths at conferences. The team hopes to upgrade the BackMap device to use a wristband format in the future.

Accessible Pi

Here at Pi Towers, we are always glad to see Pi builds for people with disabilities: we’ve seen Sanskriti and Aman’s Braille teacher Mudra, the audio e-reader Valdema by Finnish non-profit Kolibre, and Myrijam and Paul’s award-winning, eye-movement-controlled wheelchair, to name but a few.

Our mission is to bring the power of coding and digital making to everyone, and we are lucky to be part of a diverse community of makers and educators who have often worked proactively to make events and resources accessible to as many people as possible. There is, for example, the autism- and Tourette’s syndrome-friendly South London Raspberry Jam, organised by Femi Owolade-Coombes and his mum Grace. The Raspberry VI website is a portal to all things Pi for visually impaired and blind people. Deaf digital makers may find Jim Roberts’ video tutorials, which are signed in ASL, useful. And anyone can contribute subtitles in any language to our YouTube channel.

If you create or use accessible tutorials, or run a Jam, Code Club, or CoderDojo that is designed to be friendly to people who are neuroatypical or have a disability, let us know how to find your resource or event in the comments!

The post BackMap, the haptic navigation system appeared first on Raspberry Pi.

sheep-wolf – Exploit MD5 Collisions For Malware Detection

Post Syndicated from Darknet original http://feedproxy.google.com/~r/darknethackers/~3/ZBPMdkZzgOc/

sheep-wolf is a tool to help you Exploit MD5 Collisions in software, specially malware samples which are commonly detected using MD5 hash signatures. and then a malicious one (Wolf) that have the same MD5 hash. Please use this code to test if the security products in your reach use MD5 internally to fingerprint binaries and […]

The post…

Read the full post at darknet.org.uk

Build your own Crystal Maze at Home

Post Syndicated from Laura Sach original https://www.raspberrypi.org/blog/build-crystal-maze/

I recently discovered a TV channel which shows endless re-runs of the game show The Crystal Maze, and it got me thinking: what resources are available to help the younger generation experience the wonder of this iconic show? Well…

Enter the Crystal Maze

If you’re too young to remember The Crystal Maze, or if you come from a country lacking this nugget of TV gold, let me explain. A band of fairly useless contestants ran around a huge warehouse decked out to represent four zones: Industrial, Aztec, Futuristic, and Medieval. They were accompanied by a wisecracking host in a fancy coat, Richard O’Brien.

A GIF of Crystal Maze host Richard O'Brien having fun on set. Build your own Raspberry Pi Crystal Maze

Richard O’Brien also wrote The Rocky Horror Picture Show so, y’know, he was interesting to watch if nothing else.

The contestants would enter rooms to play themed challenges – the categories were mental, physical, mystery, and skill – with the aim of winning crystals. If they messed up, they were locked in the room forever (well, until the end of the episode). For every crystal they collected, they’d be given a bit more time in a giant crystal dome at the end of the programme. And what did they do in the dome? They tried to collect pieces of gold paper while being buffeted by a wind machine, of course!

A GIF of a boring prize being announced to the competing team. Build your own Raspberry Pi Crystal Maze

Collect enough gold paper and you win a mediocre prize. Fail to collect enough gold paper and you win a mediocre prize. Like I said: TV gold.

Sounds fun, doesn’t it? Here are some free resources that will help you recreate the experience of The Crystal Maze in your living room…without the fear of being locked in.

Marble maze

Image of Crystal Maze Board Game

Photo credit: Board Game Geek

Make the classic Crystal Maze game, but this time with a digital marble! Use your Sense HAT to detect pitch, roll, and yaw as you guide the marble to its destination.

Bonus fact: marble mazes featured in the Crystal Maze board game from the 1990s.

Buzz Wire

Crystal Maze Buzz Wire game screengrab

Photo credit: Board Game Geek

Guide the hook along the wire and win the crystal! Slip up and buzz three times, though, and it’s an automatic lock-in. The beauty of this make is that you can play any fail sound you like: burp wire, anyone? Follow the tutorial by community member David Pride, which he created for the Cotswold Jam.

Laser tripwire

Crystal Maze laser trip wire screengrab

Photo credit: Marc Gerrish

Why not recreate the most difficult game of all? Can you traverse a room without setting off the laser alarms, and grab the crystal? Try your skill with our laser tripwire resource!

Forget the crystal! Get out!

I would love to go to a school fête where kids build their own Crystal Maze-style challenges. I’m sure there are countless other events which you could jazz up with a fun digital making challenge, though the bald dude in a fur coat remains optional. So if you have made your own Crystal Maze challenge, or you try out one of ours, we’d love to hear about it!

Here at the Raspberry Pi Foundation, we take great pride in the wonderful free resources we produce for you to use in classes, at home, and in coding clubs. We publish them under a Creative Commons licence, and they’re an excellent way to develop your digital making skills. And massive thanks to David Pride and the Cotswold Jam for creating and sharing your great resources for free.

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