Tag Archives: Rust

Scale Your Web Application — One Step at a Time

Post Syndicated from Saurabh Shrivastava original https://aws.amazon.com/blogs/architecture/scale-your-web-application-one-step-at-a-time/

I often encounter people experiencing frustration as they attempt to scale their e-commerce or WordPress site—particularly around the cost and complexity related to scaling. When I talk to customers about their scaling plans, they often mention phrases such as horizontal scaling and microservices, but usually people aren’t sure about how to dive in and effectively scale their sites.

Now let’s talk about different scaling options. For instance if your current workload is in a traditional data center, you can leverage the cloud for your on-premises solution. This way you can scale to achieve greater efficiency with less cost. It’s not necessary to set up a whole powerhouse to light a few bulbs. If your workload is already in the cloud, you can use one of the available out-of-the-box options.

Designing your API in microservices and adding horizontal scaling might seem like the best choice, unless your web application is already running in an on-premises environment and you’ll need to quickly scale it because of unexpected large spikes in web traffic.

So how to handle this situation? Take things one step at a time when scaling and you may find horizontal scaling isn’t the right choice, after all.

For example, assume you have a tech news website where you did an early-look review of an upcoming—and highly-anticipated—smartphone launch, which went viral. The review, a blog post on your website, includes both video and pictures. Comments are enabled for the post and readers can also rate it. For example, if your website is hosted on a traditional Linux with a LAMP stack, you may find yourself with immediate scaling problems.

Let’s get more details on the current scenario and dig out more:

  • Where are images and videos stored?
  • How many read/write requests are received per second? Per minute?
  • What is the level of security required?
  • Are these synchronous or asynchronous requests?

We’ll also want to consider the following if your website has a transactional load like e-commerce or banking:

How is the website handling sessions?

  • Do you have any compliance requests—like the Payment Card Industry Data Security Standard (PCI DSS compliance) —if your website is using its own payment gateway?
  • How are you recording customer behavior data and fulfilling your analytics needs?
  • What are your loading balancing considerations (scaling, caching, session maintenance, etc.)?

So, if we take this one step at a time:

Step 1: Ease server load. We need to quickly handle spikes in traffic, generated by activity on the blog post, so let’s reduce server load by moving image and video to some third -party content delivery network (CDN). AWS provides Amazon CloudFront as a CDN solution, which is highly scalable with built-in security to verify origin access identity and handle any DDoS attacks. CloudFront can direct traffic to your on-premises or cloud-hosted server with its 113 Points of Presence (102 Edge Locations and 11 Regional Edge Caches) in 56 cities across 24 countries, which provides efficient caching.
Step 2: Reduce read load by adding more read replicas. MySQL provides a nice mirror replication for databases. Oracle has its own Oracle plug for replication and AWS RDS provide up to five read replicas, which can span across the region and even the Amazon database Amazon Aurora can have 15 read replicas with Amazon Aurora autoscaling support. If a workload is highly variable, you should consider Amazon Aurora Serverless database  to achieve high efficiency and reduced cost. While most mirror technologies do asynchronous replication, AWS RDS can provide synchronous multi-AZ replication, which is good for disaster recovery but not for scalability. Asynchronous replication to mirror instance means replication data can sometimes be stale if network bandwidth is low, so you need to plan and design your application accordingly.

I recommend that you always use a read replica for any reporting needs and try to move non-critical GET services to read replica and reduce the load on the master database. In this case, loading comments associated with a blog can be fetched from a read replica—as it can handle some delay—in case there is any issue with asynchronous reflection.

Step 3: Reduce write requests. This can be achieved by introducing queue to process the asynchronous message. Amazon Simple Queue Service (Amazon SQS) is a highly-scalable queue, which can handle any kind of work-message load. You can process data, like rating and review; or calculate Deal Quality Score (DQS) using batch processing via an SQS queue. If your workload is in AWS, I recommend using a job-observer pattern by setting up Auto Scaling to automatically increase or decrease the number of batch servers, using the number of SQS messages, with Amazon CloudWatch, as the trigger.  For on-premises workloads, you can use SQS SDK to create an Amazon SQS queue that holds messages until they’re processed by your stack. Or you can use Amazon SNS  to fan out your message processing in parallel for different purposes like adding a watermark in an image, generating a thumbnail, etc.

Step 4: Introduce a more robust caching engine. You can use Amazon Elastic Cache for Memcached or Redis to reduce write requests. Memcached and Redis have different use cases so if you can afford to lose and recover your cache from your database, use Memcached. If you are looking for more robust data persistence and complex data structure, use Redis. In AWS, these are managed services, which means AWS takes care of the workload for you and you can also deploy them in your on-premises instances or use a hybrid approach.

Step 5: Scale your server. If there are still issues, it’s time to scale your server.  For the greatest cost-effectiveness and unlimited scalability, I suggest always using horizontal scaling. However, use cases like database vertical scaling may be a better choice until you are good with sharding; or use Amazon Aurora Serverless for variable workloads. It will be wise to use Auto Scaling to manage your workload effectively for horizontal scaling. Also, to achieve that, you need to persist the session. Amazon DynamoDB can handle session persistence across instances.

If your server is on premises, consider creating a multisite architecture, which will help you achieve quick scalability as required and provide a good disaster recovery solution.  You can pick and choose individual services like Amazon Route 53, AWS CloudFormation, Amazon SQS, Amazon SNS, Amazon RDS, etc. depending on your needs.

Your multisite architecture will look like the following diagram:

In this architecture, you can run your regular workload on premises, and use your AWS workload as required for scalability and disaster recovery. Using Route 53, you can direct a precise percentage of users to an AWS workload.

If you decide to move all of your workloads to AWS, the recommended multi-AZ architecture would look like the following:

In this architecture, you are using a multi-AZ distributed workload for high availability. You can have a multi-region setup and use Route53 to distribute your workload between AWS Regions. CloudFront helps you to scale and distribute static content via an S3 bucket and DynamoDB, maintaining your application state so that Auto Scaling can apply horizontal scaling without loss of session data. At the database layer, RDS with multi-AZ standby provides high availability and read replica helps achieve scalability.

This is a high-level strategy to help you think through the scalability of your workload by using AWS even if your workload in on premises and not in the cloud…yet.

I highly recommend creating a hybrid, multisite model by placing your on-premises environment replica in the public cloud like AWS Cloud, and using Amazon Route53 DNS Service and Elastic Load Balancing to route traffic between on-premises and cloud environments. AWS now supports load balancing between AWS and on-premises environments to help you scale your cloud environment quickly, whenever required, and reduce it further by applying Amazon auto-scaling and placing a threshold on your on-premises traffic using Route 53.

BitTorrent Client Transmission Suffers Remote Takeover Vulnerability

Post Syndicated from Ernesto original https://torrentfreak.com/bittorrent-client-transmission-suffers-remote-takeover-vulnerability-180116/

With millions of active users, Transmission is one of the most used BitTorrent clients around, particularly for Mac users.

The application has been around for more than a decade and has a great reputation. However, as with any other type of software, it is not immune to vulnerabilities.

One rather concerning flaw was made public by Google vulnerability researcher Tavis Ormandy a few days ago. The flaw allows outsiders to gain access to Transmission via DNS rebinding. This ultimately allows attackers to control the BitTorrent client and execute custom code.

Ormandy has published a patch, which was also shared with the private Transmission security list at the end of November. Transmission, however, has yet to address the issue in an update.

The relatively slow response was the reason why Ormandy decided to make it public before Project Zero’s usual 90-day window expired, Ars highlights. This allows other projects to address the vulnerability right away.

“I’m finding it frustrating that the transmission developers are not responding on their private security list,” Google’s vulnerability researcher writes. “I’ve never had an opensource project take this long to fix a vulnerability before, so I usually don’t even mention the 90 day limit if the vulnerability is in an open source project.”

A member of the Transmission developer team informed Ars that they will address this ASAP, noting that the issue only affects users who have remote control enabled with the default password. This means that people who disable it or change their password can easily ‘patch’ it until the official update comes out.

Interestingly, this isn’t the last BitTorrent related vulnerability Ormandy plans to expose. According to one of his tweets on the matter, this is just the “first of a few remote code execution flaws in various popular torrent clients.”

Judging from a message the researcher sent late November, uTorrent is on the list as well. Apparently, the company’s security email address wasn’t set up correctly at the time, so BitTorrent inventor Bram Cohen has been acting as a forwarding service.

uTorrent?

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

Take a Digital Tour of an AWS Data Center to See How AWS Secures Data Centers Around The World

Post Syndicated from Chad Woolf original https://aws.amazon.com/blogs/security/take-a-digital-tour-of-an-aws-data-center-to-see-how-aws-secures-data-centers-around-the-world/

Data center tour banner image

AWS has launched a digital tour of an AWS data center, providing you with a first-ever look at how AWS secures data centers around the world. The videos, pictures, and information in this tour show you how security is intrinsic to the design of our data centers, our global controls, and the AWS culture.

As you will learn when you take this digital tour, the AWS data center security strategy is assembled with scalable security controls and multiple layers of defense that help to protect your information. For example, AWS carefully manages potential flood and seismic activity risks. We use physical barriers, security guards, threat detection technology, and an in-depth screening process to limit access to data centers. We back up our systems, regularly test equipment and processes, and continuously train AWS employees to be ready for the unexpected.

To validate the security of our data centers, external auditors perform testing on more than 2,600 standards and requirements throughout the year. Such independent examination helps ensure that security standards are consistently being met or exceeded. As a result, the most highly regulated organizations in the world trust AWS to protect their data.

Take the tour today to learn more about how we secure our data centers.

– Chad

Eevee gained 2791 experience points

Post Syndicated from Eevee original https://eev.ee/blog/2018/01/15/eevee-gained-2791-experience-points/

Eevee grew to level 31!

A year strongly defined by mixed success! Also, a lot of video games.

I ran three game jams, resulting in a total of 157 games existing that may not have otherwise, which is totally mindblowing?!

For GAMES MADE QUICK???, glip and I made NEON PHASE, a short little exploratory platformer. Honestly, I should give myself more credit for this and the rest of the LÖVE games I’ve based on the same codebase — I wove a physics engine (and everything else!) from scratch and it has held up remarkably well for a variety of different uses.

I successfully finished an HD version of Isaac’s Descent using my LÖVE engine, though it doesn’t have anything new over the original and I’ve only released it as a tech demo on Patreon.

For Strawberry Jam (NSFW!) we made fox flux (slightly NSFW!), which felt like a huge milestone: the first game where I made all the art! I mean, not counting Isaac’s Descent, which was for a very limited platform. It’s a pretty arbitrary milestone, yes, but it feels significant. I’ve been working on expanding the game into a longer and slightly less buggy experience, but the art is taking the longest by far. I must’ve spent weeks on player sprites alone.

We then set about working on Bolthaven, a sequel of sorts to NEON PHASE, and got decently far, and then abandond it. Oops.

We then started a cute little PICO-8 game, and forgot about it. Oops.

I was recruited to help with Chaos Composer, a more ambitious game glip started with someone else in Unity. I had to get used to Unity, and we squabbled a bit, but the game is finally about at the point where it’s “playable” and “maps” can be designed? It’s slightly on hold at the moment while we all finish up some other stuff, though.

We made a birthday game for two of our friends whose birthdays were very close together! Only they got to see it.

For Ludum Dare 38, we made Lunar Depot 38, a little “wave shooter” or whatever you call those? The AI is pretty rough, seeing as this was the first time I’d really made enemies and I had 72 hours to figure out how to do it, but I still think it’s pretty fun to play and I love the circular world.

I made Roguelike Simulator as an experiment with making something small and quick with a simple tool, and I had a lot of fun! I definitely want to do more stuff like this in the future.

And now we’re working on a game about Star Anise, my cat’s self-insert, which is looking to have more polish and depth than anything we’ve done so far! We’ve definitely come a long way in a year.

Somewhere along the line, I put out a call for a “potluck” project, where everyone would give me sprites of a given size without knowing what anyone else had contributed, and I would then make a game using only those sprites. Unfortunately, that stalled a few times: I tried using the Phaser JS library, but we didn’t get along; I tried LÖVE, but didn’t know where to go with the game; and then I decided to use this as an experiment with procedural generation, and didn’t get around to it. I still feel bad that everyone did work for me and I didn’t follow through, but I don’t know whether this will ever become a game.

veekun, alas, consumed months of my life. I finally got Sun and Moon loaded, but it took weeks of work since I was basically reinventing all the tooling we’d ever had from scratch, without even having most of that tooling available as a reference. It was worth it in the end, at least: Ultra Sun and Ultra Moon only took a few days to get loaded. But veekun itself is still missing some obvious Sun/Moon features, and the whole site needs an overhaul, and I just don’t know if I want to dedicate that much time to it when I have so much other stuff going on that’s much more interesting to me right now.

I finally turned my blog into more of a website, giving it a neat front page that lists a bunch of stuff I’ve done. I made a release category at last, though I’m still not quite in the habit of using it.

I wrote some blog posts, of course! I think the most interesting were JavaScript got better while I wasn’t looking and Object models. I was also asked to write a couple pieces for money for a column that then promptly shut down.

On a whim, I made a set of Eevee mugshots for Doom, which I think is a decent indication of my (pixel) art progress over the year?

I started idchoppers, a Doom parsing and manipulation library written in Rust, though it didn’t get very far and I’ve spent most of the time fighting with Rust because it won’t let me implement all my extremely bad ideas. It can do a couple things, at least, like flip maps very quickly and render maps to SVG.

I did toy around with music a little, but not a lot.

I wrote two short twines for Flora. They’re okay. I’m working on another; I think it’ll be better.

I didn’t do a lot of art overall, at least compared to the two previous years; most of my art effort over the year has gone into fox flux, which requires me to learn a whole lot of things. I did dip my toes into 3D modelling, most notably producing my current Twitter banner as well as this cool Star Anise animation. I wouldn’t mind doing more of that; maybe I’ll even try to make a low-poly pixel-textured 3D game sometime.

I restarted my book with a much better concept, though so far I’ve only written about half a chapter. Argh. I see that the vast majority of the work was done within the span of a single week, which is bad since that means I only worked on it for a week, but good since that means I can actually do a pretty good amount of work in only a week. I also did a lot of squabbling with tooling, which is hopefully mostly out of the way now.

My computer broke? That was an exciting week.


A lot of stuff, but the year as a whole still feels hit or miss. All the time I spent on veekun feels like a black void in the middle of the year, which seems like a good sign that I maybe don’t want to pour even more weeks into it in the near future.

Mostly, I want to do: more games, more art, more writing, more music.

I want to try out some tiny game making tools and make some tiny games with them — partly to get exposure to different things, partly to get more little ideas out into the world regularly, and partly to get more practice at letting myself have ideas. I have a couple tools in mind and I guess I’ll aim at a microgame every two months or so? I’d also like to finish the expanded fox flux by the end of the year, of course, though at the moment I can’t even gauge how long it might take.

I seriously lapsed on drawing last year, largely because fox flux pixel art took me so much time. So I want to draw more, and I want to get much faster at pixel art. It would probably help if I had a more concrete goal for drawing, so I might try to draw some short comics and write a little visual novel or something, which would also force me to aim for consistency.

I want to work on my book more, of course, but I also want to try my hand at a bit more fiction. I’ve had a blast writing dialogue for our games! I just shy away from longer-form writing for some reason — which seems ridiculous when a large part of my audience found me through my blog. I do think I’ve had some sort of breakthrough in the last month or two; I suddenly feel a good bit more confident about writing in general and figuring out what I want to say? One recent post I know I wrote in a single afternoon, which virtually never happens because I keep rewriting and rearranging stuff. Again, a visual novel would be a good excuse to practice writing fiction without getting too bogged down in details.

And, ah, music. I shy heavily away from music, since I have no idea what I’m doing, and also I seem to spend a lot of time fighting with tools. (Surprise.) I tried out SunVox for the first time just a few days ago and have been enjoying it quite a bit for making sound effects, so I might try it for music as well. And once again, visual novel background music is a pretty low-pressure thing to compose for. Hell, visual novels are small games, too, so that checks all the boxes. I guess I’ll go make a visual novel.

Here’s to twenty gayteen!

[$] Opening up the GnuBee open NAS system

Post Syndicated from corbet original https://lwn.net/Articles/743609/rss

GnuBee is the brand name
for a line of open hardware boards designed to provide
Linux-based network-attached storage. Given the success of the
crowdfunding campaigns for the first two products, the GB-PC1 and
GB-PC2
(which support 2.5 and 3.5 inch drives respectively), there appears to be a
market for these devices. Given that Linux is quite good at attaching
storage to a network, it seems likely they will perform their core function
more than adequately. My initial focus when exploring my GB-PC1 is not the
performance but the openness: just how open is it really? The best analogy
I can come up with is that of a door with rusty hinges: it can be opened,
but doing so requires determination.

Zero WH: pre-soldered headers and what to do with them

Post Syndicated from Alex Bate original https://www.raspberrypi.org/blog/zero-wh/

If you head over to the website of your favourite Raspberry Pi Approved Reseller today, you may find the new Zero WH available to purchase. But what it is? Why is it different, and what can you do with it?

Raspberry Pi Zero WH

“If you like pre-soldered headers, and getting caught in the rain…”

Raspberry Pi Zero WH

Imagine a Raspberry Pi Zero W. Now add a professionally soldered header. Boom, that’s the Raspberry Pi Zero WH! It’s your same great-tasting Pi, with a brand-new…crust? It’s perfect for everyone who doesn’t own a soldering iron or who wants the soldering legwork done for them.

What you can do with the Zero WH

What can’t you do? Am I right?! The small size of the Zero W makes it perfect for projects with minimal wiggle-room. In such projects, some people have no need for GPIO pins — they simply solder directly to the board. However, there are many instances where you do want a header on your Zero W, for example in order to easily take advantage of the GPIO expander tool for Debian Stretch on a PC or Mac.

GPIO expander in clubs and classrooms

As Ben Nuttall explains in his blog post on the topic:

[The GPIO expander tool] is a real game-changer for Raspberry Jams, Code Clubs, CoderDojos, and schools. You can live boot the Raspberry Pi Desktop OS from a USB stick, use Linux PCs, or even install [the Pi OS] on old computers. Then you have really simple access to physical computing without full Raspberry Pi setups, and with no SD cards to configure.

Using the GPIO expander with the Raspberry Pi Zero WH decreases the setup cost for anyone interested in trying out physical computing in the classroom or at home. (And once you’ve stuck your toes in, you’ll obviously fall in love and will soon find yourself with multiple Raspberry Pi models, HATs aplenty, and an area in your home dedicated to your new adventure in Raspberry Pi. Don’t say I didn’t warn you.)

Other uses for a Zero W with a header

The GPIO expander setup is just one of a multitude of uses for a Raspberry Pi Zero W with a header. You may want the header for prototyping before you commit to soldering wires directly to a board. Or you may have a temporary build in mind for your Zero W, in which case you won’t want to commit to soldering wires to the board at all.

Raspberry Pi Zero WH

Your use case may be something else entirely — tell us in the comments below how you’d utilise a pre-soldered Raspberry Pi Zero WH in your project. The best project idea will receive ten imaginary house points of absolutely no practical use, but immense emotional value. Decide amongst yourselves who you believe should win them — I’m going to go waste a few more hours playing SLUG!

The post Zero WH: pre-soldered headers and what to do with them appeared first on Raspberry Pi.

Yet Another FBI Proposal for Insecure Communications

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2018/01/yet_another_fbi.html

Deputy Attorney General Rosenstein has given talks where he proposes that tech companies decrease their communications and device security for the benefit of the FBI. In a recent talk, his idea is that tech companies just save a copy of the plaintext:

Law enforcement can also partner with private industry to address a problem we call “Going Dark.” Technology increasingly frustrates traditional law enforcement efforts to collect evidence needed to protect public safety and solve crime. For example, many instant-messaging services now encrypt messages by default. The prevent the police from reading those messages, even if an impartial judge approves their interception.

The problem is especially critical because electronic evidence is necessary for both the investigation of a cyber incident and the prosecution of the perpetrator. If we cannot access data even with lawful process, we are unable to do our job. Our ability to secure systems and prosecute criminals depends on our ability to gather evidence.

I encourage you to carefully consider your company’s interests and how you can work cooperatively with us. Although encryption can help secure your data, it may also prevent law enforcement agencies from protecting your data.

Encryption serves a valuable purpose. It is a foundational element of data security and essential to safeguarding data against cyber-attacks. It is critical to the growth and flourishing of the digital economy, and we support it. I support strong and responsible encryption.

I simply maintain that companies should retain the capability to provide the government unencrypted copies of communications and data stored on devices, when a court orders them to do so.

Responsible encryption is effective secure encryption, coupled with access capabilities. We know encryption can include safeguards. For example, there are systems that include central management of security keys and operating system updates; scanning of content, like your e-mails, for advertising purposes; simulcast of messages to multiple destinations at once; and key recovery when a user forgets the password to decrypt a laptop. No one calls any of those functions a “backdoor.” In fact, those very capabilities are marketed and sought out.

I do not believe that the government should mandate a specific means of ensuring access. The government does not need to micromanage the engineering.

The question is whether to require a particular goal: When a court issues a search warrant or wiretap order to collect evidence of crime, the company should be able to help. The government does not need to hold the key.

Rosenstein is right that many services like Gmail naturally keep plaintext in the cloud. This is something we pointed out in our 2016 paper: “Don’t Panic.” But forcing companies to build an alternate means to access the plaintext that the user can’t control is an enormous vulnerability.

Graphite 1.1: Teaching an Old Dog New Tricks

Post Syndicated from Blogs on Grafana Labs Blog original https://grafana.com/blog/2018/01/11/graphite-1.1-teaching-an-old-dog-new-tricks/

The Road to Graphite 1.1

I started working on Graphite just over a year ago, when @obfuscurity asked me to help out with some issues blocking the Graphite 1.0 release. Little did I know that a year later, that would have resulted in 262 commits (and counting), and that with the help of the other Graphite maintainers (especially @deniszh, @iksaif & @cbowman0) we would have added a huge amount of new functionality to Graphite.

There are a huge number of new additions and updates in this release, in this post I’ll give a tour of some of the highlights including tag support, syntax and function updates, custom function plugins, and python 3.x support.

Tagging!

The single biggest feature in this release is the addition of tag support, which brings the ability to describe metrics in a much richer way and to write more flexible and expressive queries.

Traditionally series in Graphite are identified using a hierarchical naming scheme based on dot-separated segments called nodes. This works very well and is simple to map into a hierarchical structure like the whisper filesystem tree, but it means that the user has to know what each segment represents, and makes it very difficult to modify or extend the naming scheme since everything is based on the positions of the segments within the hierarchy.

The tagging system gives users the ability to encode information about the series in a collection of tag=value pairs which are used together with the series name to uniquely identify each series, and the ability to query series by specifying tag-based matching expressions rather than constructing glob-style selectors based on the positions of specific segments within the hierarchy. This is broadly similar to the system used by Prometheus and makes it possible to use Graphite as a long-term storage backend for metrics gathered by Prometheus with full tag support.

When using tags, series names are specified using the new tagged carbon format: name;tag1=value1;tag2=value2. This format is backward compatible with most existing carbon tooling, and makes it easy to adapt existing tools to produce tagged metrics simply by changing the metric names. The OpenMetrics format is also supported for ingestion, and is normalized into the standard Graphite format internally.

At its core, the tagging system is implemented as a tag database (TagDB) alongside the metrics that allows them to be efficiently queried by individual tag values rather than having to traverse the metrics tree looking for series that match the specified query. Internally the tag index is stored in one of a number of pluggable tag databases, currently supported options are the internal graphite-web database, redis, or an external system that implements the Graphite tagging HTTP API. Carbon automatically keeps the index up to date with any tagged series seen.

The new seriesByTag function is used to query the TagDB and will return a list of all the series that match the expressions passed to it. seriesByTag supports both exact and regular expression matches, and can be used anywhere you would previously have specified a metric name or glob expression.

There are new dedicated functions for grouping and aliasing series by tag (groupByTags and aliasByTags), and you can also use tags interchangeably with node numbers in the standard Graphite functions like aliasByNode, groupByNodes, asPercent, mapSeries, etc.

Piping Syntax & Function Updates

One of the huge strengths of the Graphite render API is the ability to chain together multiple functions to process data, but until now (unless you were using a tool like Grafana) writing chained queries could be painful as each function had to be wrapped around the previous one. With this release it is now possible to “pipe” the output of one processing function into the next, and to combine piped and nested functions.

For example:

alias(movingAverage(scaleToSeconds(sumSeries(stats_global.production.counters.api.requests.*.count),60),30),'api.avg')

Can now be written as:

sumSeries(stats_global.production.counters.api.requests.*.count)|scaleToSeconds(60)|movingAverage(30)|alias('api.avg')

OR

stats_global.production.counters.api.requests.*.count|sumSeries()|scaleToSeconds(60)|movingAverage(30)|alias('api.avg')

Another source of frustration with the old function API was the inconsistent implementation of aggregations, with different functions being used in different parts of the API, and some functions simply not being available. In 1.1 all functions that perform aggregation (whether across series or across time intervals) now support a consistent set of aggregations; average, median, sum, min, max, diff, stddev, count, range, multiply and last. This is part of a new approach to implementing functions that emphasises using shared building blocks to ensure consistency across the API and solve the problem of a particular function not working with the aggregation needed for a given task.

To that end a number of new functions have been added that each provide the same functionality as an entire family of “old” functions; aggregate, aggregateWithWildcards, movingWindow, filterSeries, highest, lowest and sortBy.

Each of these functions accepts an aggregation method parameter, for example aggregate(some.metric.*, 'sum') implements the same functionality as sumSeries(some.metric.*).

It can also be used with different aggregation methods to replace averageSeries, stddevSeries, multiplySeries, diffSeries, rangeOfSeries, minSeries, maxSeries and countSeries. All those functions are now implemented as aliases for aggregate, and it supports the previously-missing median and last aggregations.

The same is true for the other functions, and the summarize, smartSummarize, groupByNode, groupByNodes and the new groupByTags functions now all support the standard set of aggregations. Gone are the days of wishing that sortByMedian or highestRange were available!

For more information on the functions available check the function documentation.

Custom Functions

No matter how many functions are available there are always going to be specific use-cases where a custom function can perform analysis that wouldn’t otherwise be possible, or provide a convenient alias for a complicated function chain or specific set of parameters.

In Graphite 1.1 we added support for easily adding one-off custom functions, as well as for creating and sharing plugins that can provide one or more functions.

Each function plugin is packaged as a simple python module, and will be automatically loaded by Graphite when placed into the functions/custom folder.

An example of a simple function plugin that translates the name of every series passed to it into UPPERCASE:

from graphite.functions.params import Param, ParamTypes

def toUpperCase(requestContext, seriesList):
  """Custom function that changes series names to UPPERCASE"""
  for series in seriesList:
    series.name = series.name.upper()
  return seriesList

toUpperCase.group = 'Custom'
toUpperCase.params = [
  Param('seriesList', ParamTypes.seriesList, required=True),
]

SeriesFunctions = {
  'upper': toUpperCase,
}

Once installed the function is not only available for use within Grpahite, but is also exposed via the new Function API which allows the function definition and documentation to be automatically loaded by tools like Grafana. This means that users will be able to select and use the new function in exactly the same way as the internal functions.

More information on writing and using custom functions is available in the documentation.

Clustering Updates

One of the biggest changes from the 0.9 to 1.0 releases was the overhaul of the clustering code, and with 1.1.1 that process has been taken even further to optimize performance when using Graphite in a clustered deployment. In the past it was common for a request to require the frontend node to make multiple requests to the backend nodes to identify matching series and to fetch data, and the code for handling remote vs local series was overly complicated. In 1.1.1 we took a new approach where all render data requests pass through the same path internally, and multiple backend nodes are handled individually rather than grouped together into a single finder. This has greatly simplified the codebase, making it much easier to understand and reason about, while allowing much more flexibility in design of the finders. After these changes, render requests can now be answered with a single internal request to each backend node, and all requests for both remote and local data are executed in parallel.

To maintain the ability of graphite to scale out horizontally, the tagging system works seamlessly within a clustered environment, with each node responsible for the series stored on that node. Calls to load tagged series via seriesByTag are fanned out to the backend nodes and results are merged on the query node just like they are for non-tagged series.

Python 3 & Django 1.11 Support

Graphite 1.1 finally brings support for Python 3.x, both graphite-web and carbon are now tested against Python 2.7, 3.4, 3.5, 3.6 and PyPy. Django releases 1.8 through 1.11 are also supported. The work involved in sorting out the compatibility issues between Python 2.x and 3.x was quite involved, but it is a huge step forward for the long term support of the project! With the new Django 2.x series supporting only Python 3.x we will need to evaluate our long-term support for Python 2.x, but the Django 1.11 series is supported through 2020 so there is time to consider the options there.

Watch This Space

Efforts are underway to add support for the new functionality across the ecosystem of tools that work with Graphite, adding collectd tagging support, prometheus remote read & write with tags (and native Prometheus remote read/write support in Graphite) and last but not least Graphite tag support in Grafana.

We’re excited about the possibilities that the new capabilities in 1.1.x open up, and can’t wait to see how the community puts them to work.

Download the 1.1.1 release and check out the release notes here.

Security updates for Wednesday

Post Syndicated from ris original https://lwn.net/Articles/743903/rss

Security updates have been issued by Debian (awstats, gdk-pixbuf, plexus-utils, and plexus-utils2), Fedora (asterisk, gimp, heimdal, libexif, linux-firmware, mupdf, poppler, thunderbird, webkitgtk4, wireshark, and xrdp), openSUSE (diffoscope, irssi, and qemu), SUSE (java-1_7_0-ibm, kernel-firmware, and qemu), and Ubuntu (irssi, kernel, linux, linux-aws, linux-euclid, linux-kvm, linux-hwe, linux-azure, linux-gcp, linux-oem, linux-lts-trusty, linux-lts-xenial, linux-lts-xenial, linux-aws, linux-raspi2, ruby1.9.1, ruby2.3, and sssd).

Daniel Miessler on My Writings about IoT Security

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2018/01/daniel_miessler.html

Daniel Miessler criticizes my writings about IoT security:

I know it’s super cool to scream about how IoT is insecure, how it’s dumb to hook up everyday objects like houses and cars and locks to the internet, how bad things can get, and I know it’s fun to be invited to talk about how everything is doom and gloom.

I absolutely respect Bruce Schneier a lot for what he’s contributed to InfoSec, which makes me that much more disappointed with this kind of position from him.

InfoSec is full of those people, and it’s beneath people like Bruce to add their voices to theirs. Everyone paying attention already knows it’s going to be a soup sandwich — a carnival of horrors — a tragedy of mistakes and abuses of trust.

It’s obvious. Not interesting. Not novel. Obvious. But obvious or not, all these things are still going to happen.

I actually agree with everything in his essay. “We should obviously try to minimize the risks, but we don’t do that by trying to shout down the entire enterprise.” Yes, definitely.

I don’t think the IoT must be stopped. I do think that the risks are considerable, and will increase as these systems become more pervasive and susceptible to class breaks. And I’m trying to write a book that will help navigate this. I don’t think I’m the prophet of doom, and don’t want to come across that way. I’ll give the manuscript another read with that in mind.

Physics cheats

Post Syndicated from Eevee original https://eev.ee/blog/2018/01/06/physics-cheats/

Anonymous asks:

something about how we tweak physics to “work” better in games?

Ho ho! Work. Get it? Like in physics…?

Hitboxes

Hitbox” is perhaps not the most accurate term, since the shape used for colliding with the environment and the shape used for detecting damage might be totally different. They’re usually the same in simple platformers, though, and that’s what most of my games have been.

The hitbox is the biggest physics fudge by far, and it exists because of a single massive approximation that (most) games make: you’re controlling a single entity in the abstract, not a physical body in great detail.

That is: when you walk with your real-world meat shell, you perform a complex dance of putting one foot in front of the other, a motion you spent years perfecting. When you walk in a video game, you press a single “walk” button. Your avatar may play an animation that moves its legs back and forth, but since you’re not actually controlling the legs independently (and since simulating them is way harder), the game just treats you like a simple shape. Fairly often, this is a box, or something very box-like.

An Eevee sprite standing on faux ground; the size of the underlying image and the hitbox are outlined

Since the player has no direct control over the exact placement of their limbs, it would be slightly frustrating to have them collide with the world. This is especially true in cases like the above, where the tail and left ear protrude significantly out from the main body. If that Eevee wanted to stand against a real-world wall, she would simply tilt her ear or tail out of the way, so there’s no reason for the ear to block her from standing against a game wall. To compensate for this, the ear and tail are left out of the collision box entirely and will simply jut into a wall if necessary — a goofy affordance that’s so common it doesn’t even register as unusual. As a bonus (assuming this same box is used for combat), she won’t take damage from projectiles that merely graze past an ear.

(One extra consideration for sprite games in particular: the hitbox ought to be horizontally symmetric around the sprite’s pivot — i.e. the point where the entity is truly considered to be standing — so that the hitbox doesn’t abruptly move when the entity turns around!)

Corners

Treating the player (and indeed most objects) as a box has one annoying side effect: boxes have corners. Corners can catch on other corners, even by a single pixel. Real-world bodies tend to be a bit rounder and squishier and this can tolerate grazing a corner; even real-world boxes will simply rotate a bit.

Ah, but in our faux physics world, we generally don’t want conscious actors (such as the player) to rotate, even with a realistic physics simulator! Real-world bodies are made of parts that will generally try to keep you upright, after all; you don’t tilt back and forth much.

One way to handle corners is to simply remove them from conscious actors. A hitbox doesn’t have to be a literal box, after all. A popular alternative — especially in Unity where it’s a standard asset — is the pill-shaped capsule, which has semicircles/hemispheres on the top and bottom and a cylindrical body in 3D. No corners, no problem.

Of course, that introduces a new problem: now the player can’t balance precariously on edges without their rounded bottom sliding them off. Alas.

If you’re stuck with corners, then, you may want to use a corner bump, a term I just made up. If the player would collide with a corner, but the collision is only by a few pixels, just nudge them to the side a bit and carry on.

An Eevee sprite trying to move sideways into a shallow ledge; the game bumps her upwards slightly, so she steps onto it instead

When the corner is horizontal, this creates stairs! This is, more or less kinda, how steps work in Doom: when the player tries to cross from one sector into another, if the height difference is 24 units or less, the game simply bumps them upwards to the height of the new floor and lets them continue on.

Implementing this in a game without Doom’s notion of sectors is a little trickier. In fact, I still haven’t done it. Collision detection based on rejection gets it for free, kinda, but it’s not very deterministic and it breaks other things. But that’s a whole other post.

Gravity

Gravity is pretty easy. Everything accelerates downwards all the time. What’s interesting are the exceptions.

Jumping

Jumping is a giant hack.

Think about how actual jumping works: you tense your legs, which generally involves bending your knees first, and then spring upwards. In a platformer, you can just leap whenever you feel like it, which is nonsense. Also you go like twenty feet into the air?

Worse, most platformers allow variable-height jumping, where your jump is lower if you let go of the jump button while you’re in the air. Normally, one would expect to have to decide how much force to put into the jump beforehand.

But of course this is about convenience of controls: when jumping is your primary action, you want to be able to do it immediately, without any windup for how high you want to jump.

(And then there’s double jumping? Come on.)

Air control is a similar phenomenon: usually you’d jump in a particular direction by controlling how you push off the ground with your feet, but in a video game, you don’t have feet! You only have the box. The compromise is to let you control your horizontal movement to a limit degree in midair, even though that doesn’t make any sense. (It’s way more fun, though, and overall gives you more movement options, which are good to have in an interactive medium.)

Air control also exposes an obvious place that game physics collide with the realistic model of serious physics engines. I’ve mentioned this before, but: if you use Real Physics™ and air control yourself into a wall, you might find that you’ll simply stick to the wall until you let go of the movement buttons. Why? Remember, player movement acts as though an external force were pushing you around (and from the perspective of a Real™ physics engine, this is exactly how you’d implement it) — so air-controlling into a wall is equivalent to pushing a book against a wall with your hand, and the friction with the wall holds you in place. Oops.

Ground sticking

Another place game physics conflict with physics engines is with running to the top of a slope. On a real hill, of course, you land on top of the slope and are probably glad of it; slopes are hard to climb!

An Eevee moves to the top of a slope, and rather than step onto the flat top, she goes flying off into the air

In a video game, you go flying. Because you’re a box. With momentum. So you hit the peak and keep going in the same direction. Which is diagonally upwards.

Projectiles

To make them more predictable, projectiles generally aren’t subject to gravity, at least as far as I’ve seen. The real world does not have such an exemption. The real world imposes gravity even on sniper rifles, which in a video game are often implemented as an instant trace unaffected by anything in the world because the bullet never actually exists in the world.

Resistance

Ah. Welcome to hell.

Water

Water is an interesting case, and offhand I don’t know the gritty details of how games implement it. In the real world, water applies a resistant drag force to movement — and that force is proportional to the square of velocity, which I’d completely forgotten until right now. I am almost positive that no game handles that correctly. But then, in real-world water, you can push against the water itself for movement, and games don’t simulate that either. What’s the rough equivalent?

The Sonic Physics Guide suggests that Sonic handles it by basically halving everything: acceleration, max speed, friction, etc. When Sonic enters water, his speed is cut; when Sonic exits water, his speed is increased.

That last bit feels validating — I could swear Metroid Prime did the same thing, and built my own solution around it, but couldn’t remember for sure. It makes no sense, of course, for a jump to become faster just because you happened to break the surface of the water, but it feels fantastic.

The thing I did was similar, except that I didn’t want to add a multiplier in a dozen places when you happen to be underwater (and remember which ones need it to be squared, etc.). So instead, I calculate everything completely as normal, so velocity is exactly the same as it would be on dry land — but the distance you would move gets halved. The effect seems to be pretty similar to most platformers with water, at least as far as I can tell. It hasn’t shown up in a published game and I only added this fairly recently, so I might be overlooking some reason this is a bad idea.

(One reason that comes to mind is that velocity is now a little white lie while underwater, so anything relying on velocity for interesting effects might be thrown off. Or maybe that’s correct, because velocity thresholds should be halved underwater too? Hm!)

Notably, air is also a fluid, so it should behave the same way (just with different constants). I definitely don’t think any games apply air drag that’s proportional to the square of velocity.

Friction

Friction is, in my experience, a little handwaved. Probably because real-world friction is so darn complicated.

Consider that in the real world, we want very high friction on the surfaces we walk on — shoes and tires are explicitly designed to increase it, even. We move by bracing a back foot against the ground and using that to push ourselves forward, so we want the ground to resist our push as much as possible.

In a game world, we are a box. We move by being pushed by some invisible outside force, so if the friction between ourselves and the ground is too high, we won’t be able to move at all! That’s complete nonsense physically, but it turns out to be handy in some cases — for example, highish friction can simulate walking through deep mud, which should be difficult due to fluid drag and low friction.

But the best-known example of the fakeness of game friction is video game ice. Walking on real-world ice is difficult because the low friction means low grip; your feet are likely to slip out from under you, and you’ll simply fall down and have trouble moving at all. In a video game, you can’t fall down, so you have the opposite experience: you spend most of your time sliding around uncontrollably. Yet ice is so common in video games (and perhaps so uncommon in places I’ve lived) that I, at least, had never really thought about this disparity until an hour or so ago.

Game friction vs real-world friction

Real-world friction is a force. It’s the normal force (which is the force exerted by the object on the surface) times some constant that depends on how the two materials interact.

Force is mass times acceleration, and platformers often ignore mass, so friction ought to be an acceleration — applied against the object’s movement, but never enough to push it backwards.

I haven’t made any games where variable friction plays a significant role, but my gut instinct is that low friction should mean the player accelerates more slowly but has a higher max speed, and high friction should mean the opposite. I see from my own source code that I didn’t even do what I just said, so let’s defer to some better-made and well-documented games: Sonic and Doom.

In Sonic, friction is a fixed value subtracted from the player’s velocity (regardless of direction) each tic. Sonic has a fixed framerate, so the units are really pixels per tic squared (i.e. acceleration), multiplied by an implicit 1 tic per tic. So far, so good.

But Sonic’s friction only applies if the player isn’t pressing or . Hang on, that isn’t friction at all; that’s just deceleration! That’s equivalent to jogging to a stop. If friction were lower, Sonic would take longer to stop, but otherwise this is only tangentially related to friction.

(In fairness, this approach would decently emulate friction for non-conscious sliding objects, which are never going to be pressing movement buttons. Also, we don’t have the Sonic source code, and the name “friction” is a fan invention; the Sonic Physics Guide already uses “deceleration” to describe the player’s acceleration when turning around.)

Okay, let’s try Doom. In Doom, the default friction is 90.625%.

Hang on, what?

Yes, in Doom, friction is a multiplier applied every tic. Doom runs at 35 tics per second, so this is a multiplier of 0.032 per second. Yikes!

This isn’t anything remotely like real friction, but it’s much easier to implement. With friction as acceleration, the game has to know both the direction of movement (so it can apply friction in the opposite direction) and the magnitude (so it doesn’t overshoot and launch the object in the other direction). That means taking a semi-costly square root and also writing extra code to cap the amount of friction. With a multiplier, neither is necessary; just multiply the whole velocity vector and you’re done.

There are some downsides. One is that objects will never actually stop, since multiplying by 3% repeatedly will never produce a result of zero — though eventually the speed will become small enough to either slip below a “minimum speed” threshold or simply no longer fit in a float representation. Another is that the units are fairly meaningless: with Doom’s default friction of 90.625%, about how long does it take for the player to stop? I have no idea, partly because “stop” is ambiguous here! If friction were an acceleration, I could divide it into the player’s max speed to get a time.

All that aside, what are the actual effects of changing Doom’s friction? What an excellent question that’s surprisingly tricky to answer. (Note that friction can’t be changed in original Doom, only in the Boom port and its derivatives.) Here’s what I’ve pieced together.

Doom’s “friction” is really two values. “Friction” itself is a multiplier applied to moving objects on every tic, but there’s also a move factor which defaults to \(\frac{1}{32} = 0.03125\) and is derived from friction for custom values.

Every tic, the player’s velocity is multiplied by friction, and then increased by their speed times the move factor.

$$
v(n) = v(n – 1) \times friction + speed \times move factor
$$

Eventually, the reduction from friction will balance out the speed boost. That happens when \(v(n) = v(n – 1)\), so we can rearrange it to find the player’s effective max speed:

$$
v = v \times friction + speed \times move factor \\
v – v \times friction = speed \times move factor \\
v = speed \times \frac{move factor}{1 – friction}
$$

For vanilla Doom’s move factor of 0.03125 and friction of 0.90625, that becomes:

$$
v = speed \times \frac{\frac{1}{32}}{1 – \frac{29}{32}} = speed \times \frac{\frac{1}{32}}{\frac{3}{32}} = \frac{1}{3} \times speed
$$

Curiously, “speed” is three times the maximum speed an actor can actually move. Doomguy’s run speed is 50, so in practice he moves a third of that, or 16⅔ units per tic. (Of course, this isn’t counting SR40, a bug that lets Doomguy run ~40% faster than intended diagonally.)

So now, what if you change friction? Even more curiously, the move factor is calculated completely differently depending on whether friction is higher or lower than the default Doom amount:

$$
move factor = \begin{cases}
\frac{133 – 128 \times friction}{544} &≈ 0.244 – 0.235 \times friction & \text{ if } friction \ge \frac{29}{32} \\
\frac{81920 \times friction – 70145}{1048576} &≈ 0.078 \times friction – 0.067 & \text{ otherwise }
\end{cases}
$$

That’s pretty weird? Complicating things further is that low friction (which means muddy terrain, remember) has an extra multiplier on its move factor, depending on how fast you’re already going — the idea is apparently that you have a hard time getting going, but it gets easier as you find your footing. The extra multiplier maxes out at 8, which makes the two halves of that function meet at the vanilla Doom value.

A graph of the relationship between friction and move factor

That very top point corresponds to the move factor from the original game. So no matter what you do to friction, the move factor becomes lower. At 0.85 and change, you can no longer move at all; below that, you move backwards.

From the formula above, it’s easy to see what changes to friction and move factor will do to Doomguy’s stable velocity. Move factor is in the numerator, so increasing it will increase stable velocity — but it can’t increase, so stable velocity can only ever decrease. Friction is in the denominator, but it’s subtracted from 1, so increasing friction will make the denominator a smaller value less than 1, i.e. increase stable velocity. Combined, we get this relationship between friction and stable velocity.

A graph showing stable velocity shooting up dramatically as friction increases

As friction approaches 1, stable velocity grows without bound. This makes sense, given the definition of \(v(n)\) — if friction is 1, the velocity from the previous tic isn’t reduced at all, so we just keep accelerating freely.

All of this is why I’m wary of using multipliers.

Anyway, this leaves me with one last question about the effects of Doom’s friction: how long does it take to reach stable velocity? Barring precision errors, we’ll never truly reach stable velocity, but let’s say within 5%. First we need a closed formula for the velocity after some number of tics. This is a simple recurrence relation, and you can write a few terms out yourself if you want to be sure this is right.

$$
v(n) = v_0 \times friction^n + speed \times move factor \times \frac{friction^n – 1}{friction – 1}
$$

Our initial velocity is zero, so the first term disappears. Set this equal to the stable formula and solve for n:

$$
speed \times move factor \times \frac{friction^n – 1}{friction – 1} = (1 – 5\%) \times speed \times \frac{move factor}{1 – friction} \\
friction^n – 1 = -(1 – 5\%) \\
n = \frac{\ln 5\%}{\ln friction}
$$

Speed” and move factor disappear entirely, which makes sense, and this is purely a function of friction (and how close we want to get). For vanilla Doom, that comes out to 30.4, which is a little less than a second. For other values of friction:

A graph of time to stability which leaps upwards dramatically towards the right

As friction increases (which in Doom terms means the surface is more slippery), it takes longer and longer to reach stable speed, which is in turn greater and greater. For lesser friction (i.e. mud), stable speed is lower, but reached fairly quickly. (Of course, the extra “getting going” multiplier while in mud adds some extra time here, but including that in the graph is a bit more complicated.)

I think this matches with my instincts above. How fascinating!

What’s that? This is way too much math and you hate it? Then don’t use multipliers in game physics.

Uh

That was a hell of a diversion!

I guess the goofiest stuff in basic game physics is really just about mapping player controls to in-game actions like jumping and deceleration; the rest consists of hacks to compensate for representing everything as a box.

New Book Coming in September: "Click Here to Kill Everybody"

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2018/01/new_book_coming.html

My next book is still on track for a September 2018 publication. Norton is still the publisher. The title is now Click Here to Kill Everybody: Peril and Promise on a Hyperconnected Planet, which I generally refer to as CH2KE.

The table of contents has changed since I last blogged about this, and it now looks like this:

  • Introduction: Everything is Becoming a Computer
  • Part 1: The Trends
    • 1. Computers are Still Hard to Secure
    • 2. Everyone Favors Insecurity
    • 3. Autonomy and Physical Agency Bring New Dangers
    • 4. Patching is Failing as a Security Paradigm
    • 5. Authentication and Identification are Getting Harder
    • 6. Risks are Becoming Catastrophic
  • Part 2: The Solutions
    • 7. What a Secure Internet+ Looks Like
    • 8. How We Can Secure the Internet+
    • 9. Government is Who Enables Security
    • 10. How Government Can Prioritize Defense Over Offense
    • 11. What’s Likely to Happen, and What We Can Do in Response
    • 12. Where Policy Can Go Wrong
    • 13. How to Engender Trust on the Internet+
  • Conclusion: Technology and Policy, Together

Two questions for everyone.

1. I’m not really happy with the subtitle. It needs to be descriptive, to counterbalance the admittedly clickbait title. It also needs to telegraph: “everyone needs to read this book.” I’m taking suggestions.

2. In the book I need a word for the Internet plus the things connected to it plus all the data and processing in the cloud. I’m using the word “Internet+,” and I’m not really happy with it. I don’t want to invent a new word, but I need to strongly signal that what’s coming is much more than just the Internet — and I can’t find any existing word. Again, I’m taking suggestions.

Spectre and Meltdown Attacks

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2018/01/spectre_and_mel.html

After a week or so of rumors, everyone is now reporting about the Spectre and Meltdown attacks against pretty much every modern processor out there.

These are side-channel attacks where one process can spy on other processes. They affect computers where an untrusted browser window can execute code, phones that have multiple apps running at the same time, and cloud computing networks that run lots of different processes at once. Fixing them either requires a patch that results in a major performance hit, or is impossible and requires a re-architecture of conditional execution in future CPU chips.

I’ll be writing something for publication over the next few days. This post is basically just a link repository.

EDITED TO ADD: Good technical explanation. And a Slashdot thread.

EDITED TO ADD (1/5): Another good technical description. And how the exploits work through browsers. A rundown of what vendors are doing. Nicholas Weaver on its effects on individual computers.

EDITED TO ADD (1/7): xkcd.

EDITED TO ADD (1/10): Another good technical description.

[$] Future directions for PGP

Post Syndicated from jake original https://lwn.net/Articles/742542/rss

Back in October, LWN reported on a talk
about the
state of the GNU Privacy Guard (GnuPG)
project, an asymmetric public-key encryption and
signing tool that had been almost abandoned by its lead developer due to lack
of resources before receiving a significant infusion of funding and community
attention. GnuPG 2 has brought about a number of changes and
improvements but,
at the same time, several efforts are underway to significantly change the way
GnuPG and OpenPGP are used. This article will look at the current
state of GnuPG and the OpenPGP web of trust, as compared to new implementations
of the OpenPGP standard and other trust systems.

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

DON’T ROLL YOUR OWN 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:

1
2
3
4
5
6
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:

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if random() < 0.8 * dt:
    do_thing()

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:

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

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:

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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:

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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,

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

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.

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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
    else:
        chance = min(80, chance + 9)

for gaps, count in sorted(histogram.items()):
    print(f"{gaps:3d} | {count / TRIALS * 100:6.2f}%", '#' * (count // (TRIALS // 100)))
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  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.

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  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.

Happy New Year- Welcome to Linux Journal 2.0

Post Syndicated from ris original https://lwn.net/Articles/742543/rss

Linux Journal is
back
. “Talk about a Happy New Year. The reason: it turns out we’re not dead. In fact, we’re more alive than ever, thanks to a rescue by readers—specifically, by the hackers who run Private Internet Access (PIA) VPN, a London Trust Media company. PIA are avid supporters of freenode and the larger FOSS community. They’re also all about Linux and the rest of the modern portfolio of allied concerns: privacy, crypto, freedom, personal agency, rewriting the rules of business and government around all of those, and having fun with constructive hacking of all kinds. We couldn’t have asked for a better rescue ship to come along for us.

2017’s “Piracy is Dangerous” Rhetoric Was Digital Reefer Madness

Post Syndicated from Andy original https://torrentfreak.com/2017s-piracy-is-dangerous-rhetoric-was-digital-reefer-madness-171230/

On dozens of occasions during the past year, TF has been compelled to cover the latest entertainment industry anti-piracy scare campaigns. We never have a problem doing so since news is to be reported and we’re all adults with our own minds to evaluate what we’re reading.

Unfortunately, many people behind these efforts seem to be under the impression that their target audience is comprised of simpletons, none of whom are blessed with a brain of their own. Frankly it’s insulting but before we go on, let’s get a few things clear.

Copyright infringement – including uploading, downloading, sharing or streaming – is illegal in most countries. That means that copyright holders are empowered under law to do something about those offenses, either through the civil or criminal courts. While unpalatable to some, most people accept that position and understand that should they be caught in the act, there might be some consequences.

With that said, there are copyright holders out there that need to stop treating people like children at best, idiots at worst. At this point in 2017, there’s no adult out there with the ability to pirate that truly believes that obtaining or sharing the latest movies, TV shows and sports is likely to be completely legal.

If you don’t believe me, ask a pirate why he or she is so excited by their fully-loaded Kodi setup. Hint: It’s because they’re getting content for free and they know full well that isn’t what the copyright holder wants. Then ask them if they want the copyright holder to know their name, address and everything they’ve downloaded. There. That’s your answer.

The point is that these people are not dumb. They know what they’re doing and understand that getting caught is something that might possibly happen. They may not understand precisely how and they may consider the risk to be particularly small (they’d be right too) but they know that it’s something best kept fairly quiet when they aren’t shouting about it to anyone who will listen down the pub.

Copyright holders aren’t dumb either. They know only too well that pirates recognize what they’re doing is probably illegal but they’re at a loss as to what to do about it. For reputable content owners, suing is expensive, doesn’t scale, is a public relations nightmare and, moreover, isn’t effective in solving the problem.

So, we now have a concerted effort to convince pirates that piracy is not only bad for their computers but also bad for their lives. It’s a stated industry aim and we’re going to see more of it in 2018.

If pirate sites aren’t infecting people’s computers with malware from God-knows-where, they’re stealing their identities and emptying their bank accounts, the industries warned in 2017. And if somehow people manage to run this gauntlet of terror without damaging their technology or their finances, then they’ll probably have their house burnt down by an exploding set-top box.

Look, the intention is understandable. Entertainment companies need to contain the piracy problem because if they don’t, it only gets worse. Again, there are few people out there who genuinely expect them to do anything different but this current stampede towards blatant scaremongering is disingenuous at best and utterly ridiculous at worst.

And it won’t work.

While piracy can be engaged in as a solo activity, it’s inherently a social phenomenon. That things can be pirated from here and there, in this way and that, is the stuff of conversations between friends and colleagues, in person and via social media. The information is passed around today like VHS and compact cassettes were passed around three decades ago and people really aren’t talking about malware or their houses catching fire.

In the somewhat unlikely event these topics do get raised for more than a minute, they get dealt with in the same way as anything else.

People inquire whether their friends have ever had their bank accounts emptied or houses burnt down, or if they know anyone who has. When the answer comes back as “no” from literally everyone, people are likely to conclude that the stories are being spread by people trying to stop them getting movies, TV shows, and live sports for free. And they would be right.

That’s not to say that these scare stories don’t have at least some basis in fact, they do.

Many pirate sites do have low-tier advertising which can put users at risk. However, it’s nothing that a decent anti-virus program and/or ad blocker can’t handle, which is something everyone should be running when accessing untrusted sites. Also, being cautious about all electronics imported from overseas is something people should be aware of too, despite the tiny risk these devices appear to pose in the scheme of things.

So, what we have here is the modern day equivalent of Reefer Madness, the 1930’s propaganda movie that tried to scare people away from marijuana with tales of car accidents, suicide, attempted rape and murder.

While somewhat more refined, these modern-day cautionary messages over piracy are destined to fall on ears that are far more shrewd and educated than their 20th-century counterparts. Yet they’re all born out of the same desire, to stop people from getting involved in an activity by warning them that it’s dangerous to them, rather than it having a negative effect on someone else – an industry executive, for example.

It’s all designed to appeal to the selfish nature of people, rather than their empathy for others, but that’s a big mistake.

Most people really do want to do the right thing, as the staggering success of Netflix, iTunes, Spotify, and Amazon show. But the ridiculous costs and/or inaccessibility of live sports, latest movies, or packaged TV shows mean that no matter what warnings get thrown out there, some people will still cut corners if they feel they’re being taken advantage of.

Worst still, if they believe the scare stories are completely ridiculous, eventually they’ll also discount the credibility of the messenger. When that happens, what little trust remains will be eroded.

Then, let’s face it, who wants to buy something from people you can’t trust?

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

Sublist3r – Fast Python Subdomain Enumeration Tool

Post Syndicated from Darknet original https://www.darknet.org.uk/2017/12/sublist3r-fast-python-subdomain-enumeration-tool/?utm_source=rss&utm_medium=social&utm_campaign=darknetfeed

Sublist3r – Fast Python Subdomain Enumeration Tool

Sublist3r is a Python-based tool designed to enumerate subdomains of websites using OSINT. It helps penetration testers and bug hunters collect and gather subdomains for the domain they are targeting.

It also integrates with subbrute for subdomain brute-forcing with word lists.

Features of Sublist3r Subdomain Enumeration Tool

It enumerates subdomains using many search engines such as:

  • Google
  • Yahoo
  • Bing
  • Baidu
  • Ask

The tool also enumerates subdomains using:

  • Netcraft
  • Virustotal
  • ThreatCrowd
  • DNSdumpster
  • ReverseDNS

Requirements of Sublist3r Subdomain Search

It currently supports Python 2 and Python 3.

Read the rest of Sublist3r – Fast Python Subdomain Enumeration Tool now! Only available at Darknet.