Entries Tagged "algorithms"

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Two NSA Algorithms Rejected by the ISO

The ISO has rejected two symmetric encryption algorithms: SIMON and SPECK. These algorithms were both designed by the NSA and made public in 2013. They are optimized for small and low-cost processors like IoT devices.

The risk of using NSA-designed ciphers, of course, is that they include NSA-designed backdoors. Personally, I doubt that they’re backdoored. And I always like seeing NSA-designed cryptography (particularly its key schedules). It’s like examining alien technology.

EDITED TO ADD (5/14): Why the algorithms were rejected.

Posted on April 25, 2018 at 6:54 AMView Comments

Lessons Learned from the Estonian National ID Security Flaw

Estonia recently suffered a major flaw in the security of their national ID card. This article discusses the fix and the lessons learned from the incident:

In the future, the infrastructure dependency on one digital identity platform must be decreased, the use of several alternatives must be encouraged and promoted. In addition, the update and replacement capacity, both remote and physical, should be increased. We also recommend the government to procure the readiness to act fast in force majeure situations from the eID providers.. While deciding on the new eID platforms, the need to replace cryptographic primitives must be taken into account — particularly the possibility of the need to replace algorithms with those that are not even in existence yet.

Posted on December 18, 2017 at 6:08 AMView Comments

Whistleblower Investigative Report on NSA Suite B Cryptography

The NSA has been abandoning secret and proprietary cryptographic algorithms in favor of commercial public algorithms, generally known as “Suite B.” In 2010, an NSA employee filed some sort of whistleblower complaint, alleging that this move is both insecure and wasteful. The US DoD Inspector General investigated and wrote a report in 2011.

The report — slightly redacted and declassified — found that there was no wrongdoing. But the report is an interesting window into the NSA’s system of algorithm selection and testing (pages 5 and 6), as well as how they investigate whistleblower complaints.

Posted on November 9, 2016 at 12:00 PMView Comments

Frequent Password Changes Is a Bad Security Idea

I’ve been saying for years that it’s bad security advice, that it encourages poor passwords. Lorrie Cranor, now the FTC’s chief technologist, agrees:

By studying the data, the researchers identified common techniques account holders used when they were required to change passwords. A password like “tarheels#1”, for instance (excluding the quotation marks) frequently became “tArheels#1” after the first change, “taRheels#1” on the second change and so on. Or it might be changed to “tarheels#11” on the first change and “tarheels#111” on the second. Another common technique was to substitute a digit to make it “tarheels#2”, “tarheels#3”, and so on.

“The UNC researchers said if people have to change their passwords every 90 days, they tend to use a pattern and they do what we call a transformation,” Cranor explained. “They take their old passwords, they change it in some small way, and they come up with a new password.”

The researchers used the transformations they uncovered to develop algorithms that were able to predict changes with great accuracy. Then they simulated real-world cracking to see how well they performed. In online attacks, in which attackers try to make as many guesses as possible before the targeted network locks them out, the algorithm cracked 17 percent of the accounts in fewer than five attempts. In offline attacks performed on the recovered hashes using superfast computers, 41 percent of the changed passwords were cracked within three seconds.

That data refers to this study.

My advice for choosing a secure password is here.

Posted on August 5, 2016 at 7:53 AMView Comments

The Fallibility of DNA Evidence

This is a good summary article on the fallibility of DNA evidence. Most interesting to me are the parts on the proprietary algorithms used in DNA matching:

William Thompson points out that Perlin has declined to make public the algorithm that drives the program. “You do have a black-box situation happening here,” Thompson told me. “The data go in, and out comes the solution, and we’re not fully informed of what happened in between.”

Last year, at a murder trial in Pennsylvania where TrueAllele evidence had been introduced, defense attorneys demanded that Perlin turn over the source code for his software, noting that “without it, [the defendant] will be unable to determine if TrueAllele does what Dr. Perlin claims it does.” The judge denied the request.


When I interviewed Perlin at Cybergenetics headquarters, I raised the matter of transparency. He was visibly annoyed. He noted that he’d published detailed papers on the theory behind TrueAllele, and filed patent applications, too: “We have disclosed not the trade secrets of the source code or the engineering details, but the basic math.”

It’s the same problem as any biometric: we need to know the rates of both false positives and false negatives. And if these algorithms are being used to determine guilt, we have a right to examine them.

EDITED TO ADD (6/13): Three more articles.

Posted on May 31, 2016 at 1:04 PMView Comments

NIST Starts Planning for Post-Quantum Cryptography

Last year, the NSA announced its plans for transitioning to cryptography that is resistant to a quantum computer. Now, it’s NIST’s turn. Its just-released report talks about the importance of algorithm agility and quantum resistance. Sometime soon, it’s going to have a competition for quantum-resistant public-key algorithms:

Creating those newer, safer algorithms is the longer-term goal, Moody says. A key part of this effort will be an open collaboration with the public, which will be invited to devise and vet cryptographic methods that — to the best of experts’ knowledge — ­will be resistant to quantum attack. NIST plans to launch this collaboration formally sometime in the next few months, but in general, Moody says it will resemble past competitions such as the one for developing the SHA-3 hash algorithm, used in part for authenticating digital messages.

“It will be a long process involving public vetting of quantum-resistant algorithms,” Moody said. “And we’re not expecting to have just one winner. There are several systems in use that could be broken by a quantum computer­ — public-key encryption and digital signatures, to take two examples­ — and we will need different solutions for each of those systems.”

The report rightly states that we’re okay in the symmetric cryptography world; the key lengths are long enough.

This is an excellent development. NIST has done an excellent job with their previous cryptographic standards, giving us a couple of good, strong, well-reviewed, and patent-free algorithms. I have no doubt this process will be equally excellent. (If NIST is keeping a list, aside from post-quantum public-key algorithms, I would like to see competitions for a larger-block-size block cipher and a super-fast stream cipher as well.)

Two news articles.

Posted on May 9, 2016 at 6:19 AMView Comments

New NIST Encryption Guidelines

NIST has published a draft of their new standard for encryption use: “NIST Special Publication 800-175B, Guideline for Using Cryptographic Standards in the Federal Government: Cryptographic Mechanisms.” In it, the Escrowed Encryption Standard from the 1990s, FIPS-185, is no longer certified. And Skipjack, NSA’s symmetric algorithm from the same period, will no longer be certified.

I see nothing sinister about decertifying Skipjack. In a world of faster computers and post-quantum thinking, an 80-bit key and 64-bit block no longer cut it.

ETA: My essays from 1998 on Skipjack and KEA.

Posted on March 17, 2016 at 9:54 AMView Comments

Sidebar photo of Bruce Schneier by Joe MacInnis.