Tag Archives: theft

Bank Card "Master Key" Stolen

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/06/bank_card_maste.html

South Africa’s Postbank experienced a catastrophic security failure. The bank’s master PIN key was stolen, forcing it to cancel and replace 12 million bank cards.

The breach resulted from the printing of the bank’s encrypted master key in plain, unencrypted digital language at the Postbank’s old data centre in the Pretoria city centre.

According to a number of internal Postbank reports, which the Sunday Times obtained, the master key was then stolen by employees.

One of the reports said that the cards would cost about R1bn to replace. The master key, a 36-digit code, allows anyone who has it to gain unfettered access to the bank’s systems, and allows them to read and rewrite account balances, and change information and data on any of the bank’s 12-million cards.

The bank lost $3.2 million in fraudulent transactions before the theft was discovered. Replacing all the cards will cost an estimated $58 million.

USB Cable Kill Switch for Laptops

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/01/usb_cable_kill_.html

BusKill is designed to wipe your laptop (Linux only) if it is snatched from you in a public place:

The idea is to connect the BusKill cable to your Linux laptop on one end, and to your belt, on the other end. When someone yanks your laptop from your lap or table, the USB cable disconnects from the laptop and triggers a udev script [1, 2, 3] that executes a series of preset operations.

These can be something as simple as activating your screensaver or shutting down your device (forcing the thief to bypass your laptop’s authentication mechanism before accessing any data), but the script can also be configured to wipe the device or delete certain folders (to prevent thieves from retrieving any sensitive data or accessing secure business backends).

Clever idea, but I — and my guess is most people — would be much more likely to stand up from the table, forgetting that the cable was attached, and yanking it out. My problem with pretty much all systems like this is the likelihood of false alarms.

Slashdot article.

EDITED TO ADD (1/14): There are Bluetooth devices that will automatically encrypt a laptop when the device isn’t in proximity. That’s a much better interface than a cable.

Chrome Extension Stealing Cryptocurrency Keys and Passwords

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/01/chrome_extensio.html

A malicious Chrome extension surreptitiously steals Ethereum keys and passwords:

According to Denley, the extension is dangerous to users in two ways. First, any funds (ETH coins and ERC0-based tokens) managed directly inside the extension are at risk.

Denley says that the extension sends the private keys of all wallets created or managed through its interface to a third-party website located at erc20wallet[.]tk.

Second, the extension also actively injects malicious JavaScript code when users navigate to five well-known and popular cryptocurrency management platforms. This code steals login credentials and private keys, data that it’s sent to the same erc20wallet[.]tk third-party website.

Another example of how blockchain requires many single points of trust in order to be secure.

GPS Manipulation

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/11/gps_manipulatio.html

Long article on the manipulation of GPS in Shanghai. It seems not to be some Chinese military program, but ships who are stealing sand.

The Shanghai “crop circles,” which somehow spoof each vessel to a different false location, are something new. “I’m still puzzled by this,” says Humphreys. “I can’t get it to work out in the math. It’s an interesting mystery.” It’s also a mystery that raises the possibility of potentially deadly accidents.

“Captains and pilots have become very dependent on GPS, because it has been historically very reliable,” says Humphreys. “If it claims to be working, they rely on it and don’t double-check it all that much.”

On June 5 this year, the Run 5678, a river cargo ship, tried to overtake a smaller craft on the Huangpu, about five miles south of the Bund. The Run avoided the small ship but plowed right into the New Glory (Chinese name: Tong Yang Jingrui), a freighter heading north.

Boing Boing article.

Details of the Cloud Hopper Attacks

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/07/details_of_the_2.html

Reuters has a long article on the Chinese government APT attack called Cloud Hopper. It was much bigger than originally reported.

The hacking campaign, known as “Cloud Hopper,” was the subject of a U.S. indictment in December that accused two Chinese nationals of identity theft and fraud. Prosecutors described an elaborate operation that victimized multiple Western companies but stopped short of naming them. A Reuters report at the time identified two: Hewlett Packard Enterprise and IBM.

Yet the campaign ensnared at least six more major technology firms, touching five of the world’s 10 biggest tech service providers.

Also compromised by Cloud Hopper, Reuters has found: Fujitsu, Tata Consultancy Services, NTT Data, Dimension Data, Computer Sciences Corporation and DXC Technology. HPE spun-off its services arm in a merger with Computer Sciences Corporation in 2017 to create DXC.

Waves of hacking victims emanate from those six plus HPE and IBM: their clients. Ericsson, which competes with Chinese firms in the strategically critical mobile telecoms business, is one. Others include travel reservation system Sabre, the American leader in managing plane bookings, and the largest shipbuilder for the U.S. Navy, Huntington Ingalls Industries, which builds America’s nuclear submarines at a Virginia shipyard.

Research on Human Honesty

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/07/research_on_hum.html

New research from Science: “Civic honesty around the globe“:

Abstract: Civic honesty is essential to social capital and economic development, but is often in conflict with material self-interest. We examine the trade-off between honesty and self-interest using field experiments in 355 cities spanning 40 countries around the globe. We turned in over 17,000 lost wallets with varying amounts of money at public and private institutions, and measured whether recipients contacted the owner to return the wallets. In virtually all countries citizens were more likely to return wallets that contained more money. Both non-experts and professional economists were unable to predict this result. Additional data suggest our main findings can be explained by a combination of altruistic concerns and an aversion to viewing oneself as a thief, which increase with the material benefits of dishonesty.

I am surprised, too.

Mail Fishing

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/03/mail_fishing.html

Not email, paper mail:

Thieves, often at night, use string to lower glue-covered rodent traps or bottles coated with an adhesive down the chute of a sidewalk mailbox. This bait attaches to the envelopes inside, and the fish in this case — mail containing gift cards, money orders or checks, which can be altered with chemicals and cashed — are reeled out slowly.

In response, the US Post Office is introducing a more secure mailbox:

The mail slots are only large enough for letters, meaning sending even small packages will require a trip to the post office. The opening is also equipped with a mechanism that grabs at a letter once inserted, making it difficult to retract.

The crime has become more common in the past few years.

Detecting Shoplifting Behavior

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/03/detecting_shopl.html

This system claims to detect suspicious behavior that indicates shoplifting:

Vaak, a Japanese startup, has developed artificial intelligence software that hunts for potential shoplifters, using footage from security cameras for fidgeting, restlessness and other potentially suspicious body language.

The article has no detail or analysis, so we don’t know how well it works. But this kind of thing is surely the future of video surveillance.

Glitter Bomb against Package Thieves

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2018/12/glitter_bomb_ag.html

Stealing packages from unattended porches is a rapidly rising crime, as more of us order more things by mail. One person hid a glitter bomb and a video recorder in a package, posting the results when thieves opened the box. At least, that’s what might have happened. At least some of the video was faked, which puts the whole thing into question.

That’s okay, though. Santa is faked, too. Happy whatever you’re celebrating.

Banks Attacked through Malicious Hardware Connected to the Local Network

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2018/12/banks_attacked_.html

Kaspersky is reporting on a series of bank hacks — called DarkVishnya — perpetrated through malicious hardware being surreptitiously installed into the target network:

In 2017-2018, Kaspersky Lab specialists were invited to research a series of cybertheft incidents. Each attack had a common springboard: an unknown device directly connected to the company’s local network. In some cases, it was the central office, in others a regional office, sometimes located in another country. At least eight banks in Eastern Europe were the targets of the attacks (collectively nicknamed DarkVishnya), which caused damage estimated in the tens of millions of dollars.

Each attack can be divided into several identical stages. At the first stage, a cybercriminal entered the organization’s building under the guise of a courier, job seeker, etc., and connected a device to the local network, for example, in one of the meeting rooms. Where possible, the device was hidden or blended into the surroundings, so as not to arouse suspicion.

The devices used in the DarkVishnya attacks varied in accordance with the cybercriminals’ abilities and personal preferences. In the cases we researched, it was one of three tools:

  • netbook or inexpensive laptop
  • Raspberry Pi computer
  • Bash Bunny, a special tool for carrying out USB attacks

Inside the local network, the device appeared as an unknown computer, an external flash drive, or even a keyboard. Combined with the fact that Bash Bunny is comparable in size to a USB flash drive, this seriously complicated the search for the entry point. Remote access to the planted device was via a built-in or USB-connected GPRS/3G/LTE modem.

Slashdot thread.

"Two Stage" BMW Theft Attempt

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2018/08/two_stage_bmw_t.html

Modern cars have alarm systems that automatically connect to a remote call center. This makes cars harder to steal, since tripping the alarm causes a quick response. This article describes a theft attempt that tried to neutralize that security system. In the first attack, the thieves just disabled the alarm system and then left. If the owner had not immediately repaired the car, the thieves would have returned the next night and — no longer working under time pressure — stolen the car.

Gas Pump Hack

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2018/07/gas_pump_hack.html

This is weird:

Police in Detroit are looking for two suspects who allegedly managed to hack a gas pump and steal over 600 gallons of gasoline, valued at about $1,800. The theft took place in the middle of the day and went on for about 90 minutes, with the gas station attendant unable to thwart the hackers.

The theft, reported by Fox 2 Detroit, took place at around 1pm local time on June 23 at a Marathon gas station located about 15 minutes from downtown Detroit. At least 10 cars are believed to have benefitted from the free-flowing gas pump, which still has police befuddled.

Here’s what is known about the supposed hack: Per Fox 2 Detroit, the thieves used some sort of remote device that allowed them to hijack the pump and take control away from the gas station employee. Police confirmed to the local publication that the device prevented the clerk from using the gas station’s system to shut off the individual pump.

Slashdot post.

Hard to know what’s true, but it seems like a good example of a hack against a cyber-physical system.

Some quick thoughts on the public discussion regarding facial recognition and Amazon Rekognition this past week

Post Syndicated from Dr. Matt Wood original https://aws.amazon.com/blogs/aws/some-quick-thoughts-on-the-public-discussion-regarding-facial-recognition-and-amazon-rekognition-this-past-week/

We have seen a lot of discussion this past week about the role of Amazon Rekognition in facial recognition, surveillance, and civil liberties, and we wanted to share some thoughts.

Amazon Rekognition is a service we announced in 2016. It makes use of new technologies – such as deep learning – and puts them in the hands of developers in an easy-to-use, low-cost way. Since then, we have seen customers use the image and video analysis capabilities of Amazon Rekognition in ways that materially benefit both society (e.g. preventing human trafficking, inhibiting child exploitation, reuniting missing children with their families, and building educational apps for children), and organizations (enhancing security through multi-factor authentication, finding images more easily, or preventing package theft). Amazon Web Services (AWS) is not the only provider of services like these, and we remain excited about how image and video analysis can be a driver for good in the world, including in the public sector and law enforcement.

There have always been and will always be risks with new technology capabilities. Each organization choosing to employ technology must act responsibly or risk legal penalties and public condemnation. AWS takes its responsibilities seriously. But we believe it is the wrong approach to impose a ban on promising new technologies because they might be used by bad actors for nefarious purposes in the future. The world would be a very different place if we had restricted people from buying computers because it was possible to use that computer to do harm. The same can be said of thousands of technologies upon which we all rely each day. Through responsible use, the benefits have far outweighed the risks.

Customers are off to a great start with Amazon Rekognition; the evidence of the positive impact this new technology can provide is strong (and growing by the week), and we’re excited to continue to support our customers in its responsible use.

-Dr. Matt Wood, general manager of artificial intelligence at AWS

Securing Your Cryptocurrency

Post Syndicated from Roderick Bauer original https://www.backblaze.com/blog/backing-up-your-cryptocurrency/

Securing Your Cryptocurrency

In our blog post on Tuesday, Cryptocurrency Security Challenges, we wrote about the two primary challenges faced by anyone interested in safely and profitably participating in the cryptocurrency economy: 1) make sure you’re dealing with reputable and ethical companies and services, and, 2) keep your cryptocurrency holdings safe and secure.

In this post, we’re going to focus on how to make sure you don’t lose any of your cryptocurrency holdings through accident, theft, or carelessness. You do that by backing up the keys needed to sell or trade your currencies.

$34 Billion in Lost Value

Of the 16.4 million bitcoins said to be in circulation in the middle of 2017, close to 3.8 million may have been lost because their owners no longer are able to claim their holdings. Based on today’s valuation, that could total as much as $34 billion dollars in lost value. And that’s just bitcoins. There are now over 1,500 different cryptocurrencies, and we don’t know how many of those have been misplaced or lost.



Now that some cryptocurrencies have reached (at least for now) staggering heights in value, it’s likely that owners will be more careful in keeping track of the keys needed to use their cryptocurrencies. For the ones already lost, however, the owners have been separated from their currencies just as surely as if they had thrown Benjamin Franklins and Grover Clevelands over the railing of a ship.

The Basics of Securing Your Cryptocurrencies

In our previous post, we reviewed how cryptocurrency keys work, and the common ways owners can keep track of them. A cryptocurrency owner needs two keys to use their currencies: a public key that can be shared with others is used to receive currency, and a private key that must be kept secure is used to spend or trade currency.

Many wallets and applications allow the user to require extra security to access them, such as a password, or iris, face, or thumb print scan. If one of these options is available in your wallets, take advantage of it. Beyond that, it’s essential to back up your wallet, either using the backup feature built into some applications and wallets, or manually backing up the data used by the wallet. When backing up, it’s a good idea to back up the entire wallet, as some wallets require additional private data to operate that might not be apparent.

No matter which backup method you use, it is important to back up often and have multiple backups, preferable in different locations. As with any valuable data, a 3-2-1 backup strategy is good to follow, which ensures that you’ll have a good backup copy if anything goes wrong with one or more copies of your data.

One more caveat, don’t reuse passwords. This applies to all of your accounts, but is especially important for something as critical as your finances. Don’t ever use the same password for more than one account. If security is breached on one of your accounts, someone could connect your name or ID with other accounts, and will attempt to use the password there, as well. Consider using a password manager such as LastPass or 1Password, which make creating and using complex and unique passwords easy no matter where you’re trying to sign in.

Approaches to Backing Up Your Cryptocurrency Keys

There are numerous ways to be sure your keys are backed up. Let’s take them one by one.

1. Automatic backups using a backup program

If you’re using a wallet program on your computer, for example, Bitcoin Core, it will store your keys, along with other information, in a file. For Bitcoin Core, that file is wallet.dat. Other currencies will use the same or a different file name and some give you the option to select a name for the wallet file.

To back up the wallet.dat or other wallet file, you might need to tell your backup program to explicitly back up that file. Users of Backblaze Backup don’t have to worry about configuring this, since by default, Backblaze Backup will back up all data files. You should determine where your particular cryptocurrency, wallet, or application stores your keys, and make sure the necessary file(s) are backed up if your backup program requires you to select which files are included in the backup.

Backblaze B2 is an option for those interested in low-cost and high security cloud storage of their cryptocurrency keys. Backblaze B2 supports 2-factor verification for account access, works with a number of apps that support automatic backups with encryption, error-recovery, and versioning, and offers an API and command-line interface (CLI), as well. The first 10GB of storage is free, which could be all one needs to store encrypted cryptocurrency keys.

2. Backing up by exporting keys to a file

Apps and wallets will let you export your keys from your app or wallet to a file. Once exported, your keys can be stored on a local drive, USB thumb drive, DAS, NAS, or in the cloud with any cloud storage or sync service you wish. Encrypting the file is strongly encouraged — more on that later. If you use 1Password or LastPass, or other secure notes program, you also could store your keys there.

3. Backing up by saving a mnemonic recovery seed

A mnemonic phrase, mnemonic recovery phrase, or mnemonic seed is a list of words that stores all the information needed to recover a cryptocurrency wallet. Many wallets will have the option to generate a mnemonic backup phrase, which can be written down on paper. If the user’s computer no longer works or their hard drive becomes corrupted, they can download the same wallet software again and use the mnemonic recovery phrase to restore their keys.

The phrase can be used by anyone to recover the keys, so it must be kept safe. Mnemonic phrases are an excellent way of backing up and storing cryptocurrency and so they are used by almost all wallets.

A mnemonic recovery seed is represented by a group of easy to remember words. For example:

eye female unfair moon genius pipe nuclear width dizzy forum cricket know expire purse laptop scale identify cube pause crucial day cigar noise receive

The above words represent the following seed:

0a5b25e1dab6039d22cd57469744499863962daba9d2844243fec 9c0313c1448d1a0b2cd9e230a78775556f9b514a8be45802c2808e fd449a20234e9262dfa69

These words have certain properties:

  • The first four letters are enough to unambiguously identify the word.
  • Similar words are avoided (such as: build and built).

Bitcoin and most other cryptocurrencies such as Litecoin, Ethereum, and others use mnemonic seeds that are 12 to 24 words long. Other currencies might use different length seeds.

4. Physical backups — Paper, Metal

Some cryptocurrency holders believe that their backup, or even all their cryptocurrency account information, should be stored entirely separately from the internet to avoid any risk of their information being compromised through hacks, exploits, or leaks. This type of storage is called “cold storage.” One method of cold storage involves printing out the keys to a piece of paper and then erasing any record of the keys from all computer systems. The keys can be entered into a program from the paper when needed, or scanned from a QR code printed on the paper.

Printed public and private keys

Printed public and private keys

Some who go to extremes suggest separating the mnemonic needed to access an account into individual pieces of paper and storing those pieces in different locations in the home or office, or even different geographical locations. Some say this is a bad idea since it could be possible to reconstruct the mnemonic from one or more pieces. How diligent you wish to be in protecting these codes is up to you.

Mnemonic recovery phrase booklet

Mnemonic recovery phrase booklet

There’s another option that could make you the envy of your friends. That’s the CryptoSteel wallet, which is a stainless steel metal case that comes with more than 250 stainless steel letter tiles engraved on each side. Codes and passwords are assembled manually from the supplied part-randomized set of tiles. Users are able to store up to 96 characters worth of confidential information. Cryptosteel claims to be fireproof, waterproof, and shock-proof.

image of a Cryptosteel cold storage device

Cryptosteel cold wallet

Of course, if you leave your Cryptosteel wallet in the pocket of a pair of ripped jeans that gets thrown out by the housekeeper, as happened to the character Russ Hanneman on the TV show Silicon Valley in last Sunday’s episode, then you’re out of luck. That fictional billionaire investor lost a USB drive with $300 million in cryptocoins. Let’s hope that doesn’t happen to you.

Encryption & Security

Whether you store your keys on your computer, an external disk, a USB drive, DAS, NAS, or in the cloud, you want to make sure that no one else can use those keys. The best way to handle that is to encrypt the backup.

With Backblaze Backup for Windows and Macintosh, your backups are encrypted in transmission to the cloud and on the backup server. Users have the option to add an additional level of security by adding a Personal Encryption Key (PEK), which secures their private key. Your cryptocurrency backup files are secure in the cloud. Using our web or mobile interface, previous versions of files can be accessed, as well.

Our object storage cloud offering, Backblaze B2, can be used with a variety of applications for Windows, Macintosh, and Linux. With B2, cryptocurrency users can choose whichever method of encryption they wish to use on their local computers and then upload their encrypted currency keys to the cloud. Depending on the client used, versioning and life-cycle rules can be applied to the stored files.

Other backup programs and systems provide some or all of these capabilities, as well. If you are backing up to a local drive, it is a good idea to encrypt the local backup, which is an option in some backup programs.

Address Security

Some experts recommend using a different address for each cryptocurrency transaction. Since the address is not the same as your wallet, this means that you are not creating a new wallet, but simply using a new identifier for people sending you cryptocurrency. Creating a new address is usually as easy as clicking a button in the wallet.

One of the chief advantages of using a different address for each transaction is anonymity. Each time you use an address, you put more information into the public ledger (blockchain) about where the currency came from or where it went. That means that over time, using the same address repeatedly could mean that someone could map your relationships, transactions, and incoming funds. The more you use that address, the more information someone can learn about you. For more on this topic, refer to Address reuse.

Note that a downside of using a paper wallet with a single key pair (type-0 non-deterministic wallet) is that it has the vulnerabilities listed above. Each transaction using that paper wallet will add to the public record of transactions associated with that address. Newer wallets, i.e. “deterministic” or those using mnemonic code words support multiple addresses and are now recommended.

There are other approaches to keeping your cryptocurrency transaction secure. Here are a couple of them.

Multi-signature

Multi-signature refers to requiring more than one key to authorize a transaction, much like requiring more than one key to open a safe. It is generally used to divide up responsibility for possession of cryptocurrency. Standard transactions could be called “single-signature transactions” because transfers require only one signature — from the owner of the private key associated with the currency address (public key). Some wallets and apps can be configured to require more than one signature, which means that a group of people, businesses, or other entities all must agree to trade in the cryptocurrencies.

Deep Cold Storage

Deep cold storage ensures the entire transaction process happens in an offline environment. There are typically three elements to deep cold storage.

First, the wallet and private key are generated offline, and the signing of transactions happens on a system not connected to the internet in any manner. This ensures it’s never exposed to a potentially compromised system or connection.

Second, details are secured with encryption to ensure that even if the wallet file ends up in the wrong hands, the information is protected.

Third, storage of the encrypted wallet file or paper wallet is generally at a location or facility that has restricted access, such as a safety deposit box at a bank.

Deep cold storage is used to safeguard a large individual cryptocurrency portfolio held for the long term, or for trustees holding cryptocurrency on behalf of others, and is possibly the safest method to ensure a crypto investment remains secure.

Keep Your Software Up to Date

You should always make sure that you are using the latest version of your app or wallet software, which includes important stability and security fixes. Installing updates for all other software on your computer or mobile device is also important to keep your wallet environment safer.

One Last Thing: Think About Your Testament

Your cryptocurrency funds can be lost forever if you don’t have a backup plan for your peers and family. If the location of your wallets or your passwords is not known by anyone when you are gone, there is no hope that your funds will ever be recovered. Taking a bit of time on these matters can make a huge difference.

To the Moon*

Are you comfortable with how you’re managing and backing up your cryptocurrency wallets and keys? Do you have a suggestion for keeping your cryptocurrencies safe that we missed above? Please let us know in the comments.


*To the Moon — Crypto slang for a currency that reaches an optimistic price projection.

The post Securing Your Cryptocurrency appeared first on Backblaze Blog | Cloud Storage & Cloud Backup.

Ray Ozzie’s Encryption Backdoor

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2018/05/ray_ozzies_encr.html

Last month, Wired published a long article about Ray Ozzie and his supposed new scheme for adding a backdoor in encrypted devices. It’s a weird article. It paints Ozzie’s proposal as something that “attains the impossible” and “satisfies both law enforcement and privacy purists,” when (1) it’s barely a proposal, and (2) it’s essentially the same key escrow scheme we’ve been hearing about for decades.

Basically, each device has a unique public/private key pair and a secure processor. The public key goes into the processor and the device, and is used to encrypt whatever user key encrypts the data. The private key is stored in a secure database, available to law enforcement on demand. The only other trick is that for law enforcement to use that key, they have to put the device in some sort of irreversible recovery mode, which means it can never be used again. That’s basically it.

I have no idea why anyone is talking as if this were anything new. Several cryptographers have already explained why this key escrow scheme is no better than any other key escrow scheme. The short answer is (1) we won’t be able to secure that database of backdoor keys, (2) we don’t know how to build the secure coprocessor the scheme requires, and (3) it solves none of the policy problems around the whole system. This is the typical mistake non-cryptographers make when they approach this problem: they think that the hard part is the cryptography to create the backdoor. That’s actually the easy part. The hard part is ensuring that it’s only used by the good guys, and there’s nothing in Ozzie’s proposal that addresses any of that.

I worry that this kind of thing is damaging in the long run. There should be some rule that any backdoor or key escrow proposal be a fully specified proposal, not just some cryptography and hand-waving notions about how it will be used in practice. And before it is analyzed and debated, it should have to satisfy some sort of basic security analysis. Otherwise, we’ll be swatting pseudo-proposals like this one, while those on the other side of this debate become increasingly convinced that it’s possible to design one of these things securely.

Already people are using the National Academies report on backdoors for law enforcement as evidence that engineers are developing workable and secure backdoors. Writing in Lawfare, Alan Z. Rozenshtein claims that the report — and a related New York Times story — “undermine the argument that secure third-party access systems are so implausible that it’s not even worth trying to develop them.” Susan Landau effectively corrects this misconception, but the damage is done.

Here’s the thing: it’s not hard to design and build a backdoor. What’s hard is building the systems — both technical and procedural — around them. Here’s Rob Graham:

He’s only solving the part we already know how to solve. He’s deliberately ignoring the stuff we don’t know how to solve. We know how to make backdoors, we just don’t know how to secure them.

A bunch of us cryptographers have already explained why we don’t think this sort of thing will work in the foreseeable future. We write:

Exceptional access would force Internet system developers to reverse “forward secrecy” design practices that seek to minimize the impact on user privacy when systems are breached. The complexity of today’s Internet environment, with millions of apps and globally connected services, means that new law enforcement requirements are likely to introduce unanticipated, hard to detect security flaws. Beyond these and other technical vulnerabilities, the prospect of globally deployed exceptional access systems raises difficult problems about how such an environment would be governed and how to ensure that such systems would respect human rights and the rule of law.

Finally, Matthew Green:

The reason so few of us are willing to bet on massive-scale key escrow systems is that we’ve thought about it and we don’t think it will work. We’ve looked at the threat model, the usage model, and the quality of hardware and software that exists today. Our informed opinion is that there’s no detection system for key theft, there’s no renewability system, HSMs are terrifically vulnerable (and the companies largely staffed with ex-intelligence employees), and insiders can be suborned. We’re not going to put the data of a few billion people on the line an environment where we believe with high probability that the system will fail.

EDITED TO ADD (5/14): An analysis of the proposal.

User Authentication Best Practices Checklist

Post Syndicated from Bozho original https://techblog.bozho.net/user-authentication-best-practices-checklist/

User authentication is the functionality that every web application shared. We should have perfected that a long time ago, having implemented it so many times. And yet there are so many mistakes made all the time.

Part of the reason for that is that the list of things that can go wrong is long. You can store passwords incorrectly, you can have a vulnerably password reset functionality, you can expose your session to a CSRF attack, your session can be hijacked, etc. So I’ll try to compile a list of best practices regarding user authentication. OWASP top 10 is always something you should read, every year. But that might not be enough.

So, let’s start. I’ll try to be concise, but I’ll include as much of the related pitfalls as I can cover – e.g. what could go wrong with the user session after they login:

  • Store passwords with bcrypt/scrypt/PBKDF2. No MD5 or SHA, as they are not good for password storing. Long salt (per user) is mandatory (the aforementioned algorithms have it built in). If you don’t and someone gets hold of your database, they’ll be able to extract the passwords of all your users. And then try these passwords on other websites.
  • Use HTTPS. Period. (Otherwise user credentials can leak through unprotected networks). Force HTTPS if user opens a plain-text version.
  • Mark cookies as secure. Makes cookie theft harder.
  • Use CSRF protection (e.g. CSRF one-time tokens that are verified with each request). Frameworks have such functionality built-in.
  • Disallow framing (X-Frame-Options: DENY). Otherwise your website may be included in another website in a hidden iframe and “abused” through javascript.
  • Have a same-origin policy
  • Logout – let your users logout by deleting all cookies and invalidating the session. This makes usage of shared computers safer (yes, users should ideally use private browsing sessions, but not all of them are that savvy)
  • Session expiry – don’t have forever-lasting sessions. If the user closes your website, their session should expire after a while. “A while” may still be a big number depending on the service provided. For ajax-heavy website you can have regular ajax-polling that keeps the session alive while the page stays open.
  • Remember me – implementing “remember me” (on this machine) functionality is actually hard due to the risks of a stolen persistent cookie. Spring-security uses this approach, which I think should be followed if you wish to implement more persistent logins.
  • Forgotten password flow – the forgotten password flow should rely on sending a one-time (or expiring) link to the user and asking for a new password when it’s opened. 0Auth explain it in this post and Postmark gives some best pracitces. How the link is formed is a separate discussion and there are several approaches. Store a password-reset token in the user profile table and then send it as parameter in the link. Or do not store anything in the database, but send a few params: userId:expiresTimestamp:hmac(userId+expiresTimestamp). That way you have expiring links (rather than one-time links). The HMAC relies on a secret key, so the links can’t be spoofed. It seems there’s no consensus, as the OWASP guide has a bit different approach
  • One-time login links – this is an option used by Slack, which sends one-time login links instead of asking users for passwords. It relies on the fact that your email is well guarded and you have access to it all the time. If your service is not accessed to often, you can have that approach instead of (rather than in addition to) passwords.
  • Limit login attempts – brute-force through a web UI should not be possible; therefore you should block login attempts if they become too many. One approach is to just block them based on IP. The other one is to block them based on account attempted. (Spring example here). Which one is better – I don’t know. Both can actually be combined. Instead of fully blocking the attempts, you may add a captcha after, say, the 5th attempt. But don’t add the captcha for the first attempt – it is bad user experience.
  • Don’t leak information through error messages – you shouldn’t allow attackers to figure out if an email is registered or not. If an email is not found, upon login report just “Incorrect credentials”. On passwords reset, it may be something like “If your email is registered, you should have received a password reset email”. This is often at odds with usability – people don’t often remember the email they used to register, and the ability to check a number of them before getting in might be important. So this rule is not absolute, though it’s desirable, especially for more critical systems.
  • Make sure you use JWT only if it’s really necessary and be careful of the pitfalls.
  • Consider using a 3rd party authentication – OpenID Connect, OAuth by Google/Facebook/Twitter (but be careful with OAuth flaws as well). There’s an associated risk with relying on a 3rd party identity provider, and you still have to manage cookies, logout, etc., but some of the authentication aspects are simplified.
  • For high-risk or sensitive applications use 2-factor authentication. There’s a caveat with Google Authenticator though – if you lose your phone, you lose your accounts (unless there’s a manual process to restore it). That’s why Authy seems like a good solution for storing 2FA keys.

I’m sure I’m missing something. And you see it’s complicated. Sadly we’re still at the point where the most common functionality – authenticating users – is so tricky and cumbersome, that you almost always get at least some of it wrong.

The post User Authentication Best Practices Checklist appeared first on Bozho's tech blog.

Tracing Stolen Bitcoin

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2018/03/tracing_stolen_.html

Ross Anderson has a really interesting paper on tracing stolen bitcoin. From a blog post:

Previous attempts to track tainted coins had used either the “poison” or the “haircut” method. Suppose I open a new address and pay into it three stolen bitcoin followed by seven freshly-mined ones. Then under poison, the output is ten stolen bitcoin, while under haircut it’s ten bitcoin that are marked 30% stolen. After thousands of blocks, poison tainting will blacklist millions of addresses, while with haircut the taint gets diffused, so neither is very effective at tracking stolen property. Bitcoin due-diligence services supplant haircut taint tracking with AI/ML, but the results are still not satisfactory.

We discovered that, back in 1816, the High Court had to tackle this problem in Clayton’s case, which involved the assets and liabilities of a bank that had gone bust. The court ruled that money must be tracked through accounts on the basis of first-in, first out (FIFO); the first penny into an account goes to satisfy the first withdrawal, and so on.

Ilia Shumailov has written software that applies FIFO tainting to the blockchain and the results are impressive, with a massive improvement in precision. What’s more, FIFO taint tracking is lossless, unlike haircut; so in addition to tracking a stolen coin forward to find where it’s gone, you can start with any UTXO and trace it backwards to see its entire ancestry. It’s not just good law; it’s good computer science too.

Jackpotting Attacks Against US ATMs

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2018/02/jackpotting_att.html

Brian Krebs is reporting sophisticated jackpotting attacks against US ATMs. The attacker gains physical access to the ATM, plants malware using specialized electronics, and then later returns and forces the machine to dispense all the cash it has inside.

The Secret Service alert explains that the attackers typically use an endoscope — a slender, flexible instrument traditionally used in medicine to give physicians a look inside the human body — to locate the internal portion of the cash machine where they can attach a cord that allows them to sync their laptop with the ATM’s computer.

“Once this is complete, the ATM is controlled by the fraudsters and the ATM will appear Out of Service to potential customers,” reads the confidential Secret Service alert.

At this point, the crook(s) installing the malware will contact co-conspirators who can remotely control the ATMs and force the machines to dispense cash.

“In previous Ploutus.D attacks, the ATM continuously dispensed at a rate of 40 bills every 23 seconds,” the alert continues. Once the dispense cycle starts, the only way to stop it is to press cancel on the keypad. Otherwise, the machine is completely emptied of cash, according to the alert.

Lots of details in the article.