Entries Tagged "encryption"

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Signal Adds Cryptocurrency Support

According to Wired, Signal is adding support for the cryptocurrency MobileCoin, “a form of digital cash designed to work efficiently on mobile devices while protecting users’ privacy and even their anonymity.”

Moxie Marlinspike, the creator of Signal and CEO of the nonprofit that runs it, describes the new payments feature as an attempt to extend Signal’s privacy protections to payments with the same seamless experience that Signal has offered for encrypted conversations. “There’s a palpable difference in the feeling of what it’s like to communicate over Signal, knowing you’re not being watched or listened to, versus other communication platforms,” Marlinspike told WIRED in an interview. “I would like to get to a world where not only can you feel that when you talk to your therapist over Signal, but also when you pay your therapist for the session over Signal.”

I think this is an incredibly bad idea. It’s not just the bloating of what was a clean secure communications app. It’s not just that blockchain is just plain stupid. It’s not even that Signal is choosing to tie itself to a specific blockchain currency. It’s that adding a cryptocurrency to an end-to-end encrypted app muddies the morality of the product, and invites all sorts of government investigative and regulatory meddling: by the IRS, the SEC, FinCEN, and probably the FBI.

And I see no good reason to do this. Secure communications and secure transactions can be separate apps, even separate apps from the same organization. End-to-end encryption is already at risk. Signal is the best app we have out there. Combining it with a cryptocurrency means that the whole system dies if any part dies.

EDITED TO ADD: Commentary from Stephen Deihl:

I think I speak for many technologists when I say that any bolted-on cryptocurrency monetization scheme smells like a giant pile of rubbish and feels enormously user-exploitative. We’ve seen this before, after all Telegram tried the same thing in an ICO that imploded when SEC shut them down, and Facebook famously tried and failed to monetize WhatsApp through their decentralized-but-not-really digital money market fund project.

[…]

Signal is a still a great piece of software. Just do one thing and do it well, be the trusted de facto platform for private messaging that empowers dissidents, journalists and grandma all to communicate freely with the same guarantees of privacy. Don’t become a dodgy money transmitter business. This is not the way.

EDITED TO ADD (4/14): Moxie Marlinspike is on the advisory board for MobileCoin, which was designed for the purpose of providing a payment function in Signal.

Posted on April 7, 2021 at 6:24 AMView Comments

Brexit Deal Mandates Old Insecure Crypto Algorithms

In what is surely an unthinking cut-and-paste issue, page 921 of the Brexit deal mandates the use of SHA-1 and 1024-bit RSA:

The open standard s/MIME as extension to de facto e-mail standard SMTP will be deployed to encrypt messages containing DNA profile information. The protocol s/MIME (V3) allows signed receipts, security labels, and secure mailing lists… The underlying certificate used by s/MIME mechanism has to be in compliance with X.509 standard…. The processing rules for s/MIME encryption operations… are as follows:

  1. the sequence of the operations is: first encryption and then signing,
  2. the encryption algorithm AES (Advanced Encryption Standard) with 256 bit key length and RSA with 1,024 bit key length shall be applied for symmetric and asymmetric encryption respectively,
  3. the hash algorithm SHA-1 shall be applied.
  4. s/MIME functionality is built into the vast majority of modern e-mail software packages including Outlook, Mozilla Mail as well as Netscape Communicator 4.x and inter-operates among all major e-mail software packages.

And s/MIME? Bleah.

Posted on December 31, 2020 at 6:19 AMView Comments

Cellebrite Can Break Signal

Cellebrite announced that it can break Signal. (Note that the company has heavily edited its blog post, but the original — with lots of technical details — was saved by the Wayback Machine.)

News article. Slashdot post.

The whole story is puzzling. Cellebrite’s details will make it easier for the Signal developers to patch the vulnerability. So either Cellebrite believes it is so good that it can break whatever Signal does, or the original blog post was a mistake.

EDITED TO ADD (12/22): Signal’s Moxie Marlinspike takes serious issue with Cellebrite’s announcement. I have urged him to write it up, and will link to it when he does.

EDITED TO ADD (12/23): I need to apologize for this post. I finally got the chance to read all of this more carefully, and it seems that all Cellebrite is doing is reading the texts off of a phone they can already access. To this has nothing to do with Signal at all. So: never mind. False alarm. Apologies, again.

Posted on December 21, 2020 at 6:06 AMView Comments

Zodiac Killer Cipher Solved

The SF Chronicle is reporting (more details here), and the FBI is confirming, that a Melbourne mathematician and team has decrypted the 1969 message sent by the Zodiac Killer to the newspaper.

There’s no paper yet, but there are a bunch of details in the news articles.

Here’s an interview with one of the researchers:

Cryptologist David Oranchak, who has been trying to crack the notorious “340 cipher” (it contains 340 characters) for more than a decade, made a crucial breakthrough earlier this year when applied mathematician Sam Blake came up with about 650,000 different possible ways in which the code could be read. From there, using code-breaking software designed by Jarl Van Eycke, the team’s third member, they came up with a small number of valuable clues that helped them piece together a message in the cipher

Posted on December 16, 2020 at 7:01 AMView Comments

Indistinguishability Obfuscation

Quanta magazine recently published a breathless article on indistinguishability obfuscation — calling it the “‘crown jewel’ of cryptography” — and saying that it had finally been achieved, based on a recently published paper. I want to add some caveats to the discussion.

Basically, obfuscation makes a computer program “unintelligible” by performing its functionality. Indistinguishability obfuscation is more relaxed. It just means that two different programs that perform the same functionality can’t be distinguished from each other. A good definition is in this paper.

This is a pretty amazing theoretical result, and one to be excited about. We can now do obfuscation, and we can do it using assumptions that make real-world sense. The proofs are kind of ugly, but that’s okay — it’s a start. What it means in theory is that we have a fundamental theoretical result that we can use to derive a whole bunch of other cryptographic primitives.

But — and this is a big one — this result is not even remotely close to being practical. We’re talking multiple days to perform pretty simple calculations, using massively large blocks of computer code. And this is likely to remain true for a very long time. Unless researchers increase performance by many orders of magnitude, nothing in the real world will make use of this work anytime soon.

But but, consider fully homomorphic encryption. It, too, was initially theoretically interesting and completely impractical. And now, after decades of work, it seems to be almost just-barely maybe approaching practically useful. This could very well be on the same trajectory, and perhaps in twenty to thirty years we will be celebrating this early theoretical result as the beginning of a new theory of cryptography.

Posted on November 23, 2020 at 6:04 AMView Comments

New Report on Police Decryption Capabilities

There is a new report on police decryption capabilities: specifically, mobile device forensic tools (MDFTs). Short summary: it’s not just the FBI that can do it.

This report documents the widespread adoption of MDFTs by law enforcement in the United States. Based on 110 public records requests to state and local law enforcement agencies across the country, our research documents more than 2,000 agencies that have purchased these tools, in all 50 states and the District of Columbia. We found that state and local law enforcement agencies have performed hundreds of thousands of cellphone extractions since 2015, often without a warrant. To our knowledge, this is the first time that such records have been widely disclosed.

Lots of details in the report. And in this news article:

At least 49 of the 50 largest U.S. police departments have the tools, according to the records, as do the police and sheriffs in small towns and counties across the country, including Buckeye, Ariz.; Shaker Heights, Ohio; and Walla Walla, Wash. And local law enforcement agencies that don’t have such tools can often send a locked phone to a state or federal crime lab that does.

[…]

The tools mostly come from Grayshift, an Atlanta company co-founded by a former Apple engineer, and Cellebrite, an Israeli unit of Japan’s Sun Corporation. Their flagship tools cost roughly $9,000 to $18,000, plus $3,500 to $15,000 in annual licensing fees, according to invoices obtained by Upturn.

Posted on October 23, 2020 at 8:47 AMView Comments

BlackBerry Phone Cracked

Australia is reporting that a BlackBerry device has been cracked after five years:

An encrypted BlackBerry device that was cracked five years after it was first seized by police is poised to be the key piece of evidence in one of the state’s longest-running drug importation investigations.

In April, new technology “capabilities” allowed authorities to probe the encrypted device….

No details about those capabilities.

Posted on August 3, 2020 at 11:54 AMView Comments

On the Twitter Hack

Twitter was hacked this week. Not a few people’s Twitter accounts, but all of Twitter. Someone compromised the entire Twitter network, probably by stealing the log-in credentials of one of Twitter’s system administrators. Those are the people trusted to ensure that Twitter functions smoothly.

The hacker used that access to send tweets from a variety of popular and trusted accounts, including those of Joe Biden, Bill Gates, and Elon Musk, as part of a mundane scam — stealing bitcoin — but it’s easy to envision more nefarious scenarios. Imagine a government using this sort of attack against another government, coordinating a series of fake tweets from hundreds of politicians and other public figures the day before a major election, to affect the outcome. Or to escalate an international dispute. Done well, it would be devastating.

Whether the hackers had access to Twitter direct messages is not known. These DMs are not end-to-end encrypted, meaning that they are unencrypted inside Twitter’s network and could have been available to the hackers. Those messages — between world leaders, industry CEOs, reporters and their sources, heath organizations — are much more valuable than bitcoin. (If I were a national-intelligence agency, I might even use a bitcoin scam to mask my real intelligence-gathering purpose.) Back in 2018, Twitter said it was exploring encrypting those messages, but it hasn’t yet.

Internet communications platforms — such as Facebook, Twitter, and YouTube — are crucial in today’s society. They’re how we communicate with one another. They’re how our elected leaders communicate with us. They are essential infrastructure. Yet they are run by for-profit companies with little government oversight. This is simply no longer sustainable. Twitter and companies like it are essential to our national dialogue, to our economy, and to our democracy. We need to start treating them that way, and that means both requiring them to do a better job on security and breaking them up.

In the Twitter case this week, the hacker’s tactics weren’t particularly sophisticated. We will almost certainly learn about security lapses at Twitter that enabled the hack, possibly including a SIM-swapping attack that targeted an employee’s cellular service provider, or maybe even a bribed insider. The FBI is investigating.

This kind of attack is known as a “class break.” Class breaks are endemic to computerized systems, and they’re not something that we as users can defend against with better personal security. It didn’t matter whether individual accounts had a complicated and hard-to-remember password, or two-factor authentication. It didn’t matter whether the accounts were normally accessed via a Mac or a PC. There was literally nothing any user could do to protect against it.

Class breaks are security vulnerabilities that break not just one system, but an entire class of systems. They might exploit a vulnerability in a particular operating system that allows an attacker to take remote control of every computer that runs on that system’s software. Or a vulnerability in internet-enabled digital video recorders and webcams that allows an attacker to recruit those devices into a massive botnet. Or a single vulnerability in the Twitter network that allows an attacker to take over every account.

For Twitter users, this attack was a double whammy. Many people rely on Twitter’s authentication systems to know that someone who purports to be a certain celebrity, politician, or journalist is really that person. When those accounts were hijacked, trust in that system took a beating. And then, after the attack was discovered and Twitter temporarily shut down all verified accounts, the public lost a vital source of information.

There are many security technologies companies like Twitter can implement to better protect themselves and their users; that’s not the issue. The problem is economic, and fixing it requires doing two things. One is regulating these companies, and requiring them to spend more money on security. The second is reducing their monopoly power.

The security regulations for banks are complex and detailed. If a low-level banking employee were caught messing around with people’s accounts, or if she mistakenly gave her log-in credentials to someone else, the bank would be severely fined. Depending on the details of the incident, senior banking executives could be held personally liable. The threat of these actions helps keep our money safe. Yes, it costs banks money; sometimes it severely cuts into their profits. But the banks have no choice.

The opposite is true for these tech giants. They get to decide what level of security you have on your accounts, and you have no say in the matter. If you are offered security and privacy options, it’s because they decided you can have them. There is no regulation. There is no accountability. There isn’t even any transparency. Do you know how secure your data is on Facebook, or in Apple’s iCloud, or anywhere? You don’t. No one except those companies do. Yet they’re crucial to the country’s national security. And they’re the rare consumer product or service allowed to operate without significant government oversight.

For example, President Donald Trump’s Twitter account wasn’t hacked as Joe Biden’s was, because that account has “special protections,” the details of which we don’t know. We also don’t know what other world leaders have those protections, or the decision process surrounding who gets them. Are they manual? Can they scale? Can all verified accounts have them? Your guess is as good as mine.

In addition to security measures, the other solution is to break up the tech monopolies. Companies like Facebook and Twitter have so much power because they are so large, and they face no real competition. This is a national-security risk as well as a personal-security risk. Were there 100 different Twitter-like companies, and enough compatibility so that all their feeds could merge into one interface, this attack wouldn’t have been such a big deal. More important, the risk of a similar but more politically targeted attack wouldn’t be so great. If there were competition, different platforms would offer different security options, as well as different posting rules, different authentication guidelines — different everything. Competition is how our economy works; it’s how we spur innovation. Monopolies have more power to do what they want in the quest for profits, even if it harms people along the way.

This wasn’t Twitter’s first security problem involving trusted insiders. In 2017, on his last day of work, an employee shut down President Donald Trump’s account. In 2019, two people were charged with spying for the Saudi government while they were Twitter employees.

Maybe this hack will serve as a wake-up call. But if past incidents involving Twitter and other companies are any indication, it won’t. Underspending on security, and letting society pay the eventual price, is far more profitable. I don’t blame the tech companies. Their corporate mandate is to make as much money as is legally possible. Fixing this requires changes in the law, not changes in the hearts of the company’s leaders.

This essay previously appeared on TheAtlantic.com.

EDITED TO ADD: This essay has been translated into Czech.

EDITED TO ADD: This essay has been translated into Spanish.

Posted on July 20, 2020 at 8:49 AMView Comments

Sidebar photo of Bruce Schneier by Joe MacInnis.