Entries Tagged "cryptography"

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Perpetual Doghouse: Meganet

I first wrote about Meganet in 1999, in a larger article on cryptographic snake-oil, and formally put them in the doghouse in 2003:

They build an alternate reality where every cryptographic algorithm has been broken, and the only thing left is their own system. “The weakening of public crypto systems commenced in 1997. First it was the 40-bit key, a few months later the 48-bit key, followed by the 56-bit key, and later the 512 bit has been broken…” What are they talking about? Would you trust a cryptographer who didn’t know the difference between symmetric and public-key cryptography? “Our technology… is the only unbreakable encryption commercially available.” The company’s founder quoted in a news article: “All other encryption methods have been compromised in the last five to six years.” Maybe in their alternate reality, but not in the one we live in.

Their solution is to not encrypt data at all. “We believe there is one very simple rule in encryption: if someone can encrypt data, someone else will be able to decrypt it. The idea behind VME is that the data is not being encrypted nor transferred. And if it’s not encrypted and not transferred, there is nothing to break. And if there’s nothing to break, it’s unbreakable.” Ha ha; that’s a joke. They really do encrypt data, but they call it something else.

Read the whole thing; it’s pretty funny.

They’re still around, and they’re still touting their snake-oil “virtual matrix encryption.” (The patent is finally public, and if someone can reverse-engineer the combination of patentese and gobbledygook into an algorithm, we can finally see how actually awful it really is.) The tech on their website is better than it was in 2003, but it’s still pretty hokey.

Back in 2005, they got their product FIPS 140-1 certified (#505 on this page). The certification was for their AES implementation, but they’re sneakily implying that VME was certified. From their website: “The Strength of a Megabit Encryption (VME). The Assurance of a 256 Bit Standard (AES). Both Technologies Combined in One Certified Module! FIPS 140-2 CERTIFICATE # 505.”

Just goes to show that with a bit of sleight-of-hand you can get anything FIPS 140 certified.

Posted on June 14, 2007 at 1:05 PM • View Comments

More on Kish's Encryption Scheme

Back in 2005, I wrote about Laszlo Kish’s encryption scheme, which promises the security of quantum encryption using thermal noise. I found, and continue to find, the research fascinating—although I don’t have the electrical engineering expertise to know whether or not it’s secure.

There have been developments. Kish has a new paper that not only describes a physical demonstration of the scheme, but also addresses many of the criticisms of his earlier work. And Feng Hao has a new paper that claims the scheme is totally insecure.

Again, I don’t have the EE background to know who’s right. But this is exactly the sort of back-and-forth I want to see.

Posted on June 11, 2007 at 6:49 AM • View Comments

307-Digit Number Factored

We have a new factoring record: 307 digits. It’s a special number—2^1039 – 1—but the techniques can be generalized:

Is the writing on the wall for 1024-bit encryption” “The answer to that question is an unqualified yes,” says Lenstra. For the moment the standard is still secure, because it is much more difficult to factor a number made up of two huge prime numbers, such as an RSA number, than it is to factor a number like this one that has a special mathematical form. But the clock is definitely ticking. “Last time, it took nine years for us to generalize from a special to a non-special hard-to factor number (155 digits). I won’t make predictions, but let’s just say it might be a good idea to stay tuned.”

I hope RSA applications would have moved away from 1024-bit security years ago, but for those who haven’t yet: wake up.

EDITED TO ADD (5/21): That’s 1023 bits. (I should have said that.)

Posted on May 21, 2007 at 10:26 AM • View Comments

Quantum Computation Research Center in Singapore

Singapore is setting up a $98M research center for quantum computation.

Great news, but what in the world does this quote mean?

Professor Artur Ekert, Director, Research Centre of Excellence, said: “At the moment, you can buy quantum cryptography systems, you can use it in some simple applications but somehow you have to trust companies that sell it to you or you have to test the equipment.

“The kind of quantum cryptography we develop here is probably the most sophisticated that is not available in any other countries so we have some ideas to make it so secure that you don’t even have to trust equipment that you could buy from a vendor.”

Posted on May 10, 2007 at 1:08 PM • View Comments

Dept of Homeland Security Wants DNSSEC Keys

This is a big deal:

The shortcomings of the present DNS have been known for years but difficulties in devising a system that offers backward compatability while scaling to millions of nodes on the net have slowed down the implementation of its successor, Domain Name System Security Extensions (DNSSEC). DNSSEC ensures that domain name requests are digitally signed and authenticated, a defence against forged DNS data, a product of attacks such as DNS cache poisoning used to trick surfers into visiting bogus websites that pose as the real thing.

Obtaining the master key for the DNS root zone would give US authorities the ability to track DNS Security Extensions (DNSSec) “all the way back to the servers that represent the name system’s root zone on the internet”.

Access to the “key-signing key” would give US authorities a supervisory role over DNS lookups, vital for functions ranging from email delivery to surfing the net. At a recent ICANN meeting in Lisbon, Bernard Turcotte, president of the Canadian Internet Registration Authority, said managers of country registries were concerned about the proposal to allow the US to control the master keys, giving it privileged control of internet resources, Heise reports.

Another news report.

Posted on April 9, 2007 at 9:45 AM • View Comments

Breaking WEP in Under a Minute

WEP (Wired Equivalent Privacy) was the protocol used to secure wireless networks. It’s known to be insecure and has been replaced by Wi-Fi Protected Access, but it’s still in use.

This paper, “Breaking 104 bit WEP in less than 60 seconds,” is the best attack against WEP to date:

Abstract:

We demonstrate an active attack on the WEP protocol that is able to recover a 104-bit WEP key using less than 40.000 frames with a success probability of 50%. In order to succeed in 95% of all cases, 85.000 packets are needed. The IV of these packets can be randomly chosen. This is an improvement in the number of required frames by more than an order of magnitude over the best known key-recovery attacks for WEP. On a IEEE 802.11g network, the number of frames required can be obtained by re-injection in less than a minute. The required computational effort is approximately 2^20 RC4 key setups, which on current desktop and laptop CPUs in negligible.

Posted on April 4, 2007 at 12:46 PM • View Comments

More AACS Cracking

Slowly, AACS—the security in both Blu-ray and HD DVD—has been cracked. Now, it has been cracked even further:

Arnezami, a hacker on the Doom9 forum, has published a crack for extracting the “processing key” from a high-def DVD player. This key can be used to gain access to every single Blu-Ray and HD-DVD disc.

Previously, another Doom9 user called Muslix64 had broken both Blu-Ray and HD-DVD by extracting the “volume keys” for each disc, a cumbersome process. This break builds on Muslix64’s work but extends it—now you can break all AACS-locked discs.

As I have said before, what will be interesting to watch is how well HD DVD and Blu-ray recover. Both were built expecting these sorts of cracks, and both have mechanisms to recover security for future movies. It remains to be seen how well these recovery systems will work.

Posted on February 19, 2007 at 1:28 PM • View Comments

A New Secure Hash Standard

The U.S. National Institute of Standards and Technology is having a competition for a new cryptographic hash function.

This matters. The phrase “one-way hash function” might sound arcane and geeky, but hash functions are the workhorses of modern cryptography. They provide web security in SSL. They help with key management in e-mail and voice encryption: PGP, Skype, all the others. They help make it harder to guess passwords. They’re used in virtual private networks, help provide DNS security and ensure that your automatic software updates are legitimate. They provide all sorts of security functions in your operating system. Every time you do something with security on the internet, a hash function is involved somewhere.

Basically, a hash function is a fingerprint function. It takes a variable-length input—anywhere from a single byte to a file terabytes in length—and converts it to a fixed-length string: 20 bytes, for example.

One-way hash functions are supposed to have two properties. First, they’re one-way. This means that it is easy to take an input and compute the hash value, but it’s impossible to take a hash value and recreate the original input. By “impossible” I mean “can’t be done in any reasonable amount of time.”

Second, they’re collision-free. This means that even though there are an infinite number of inputs for every hash value, you’re never going to find two of them. Again, “never” is defined as above. The cryptographic reasoning behind these two properties is subtle, but any cryptographic text talks about them.

The hash function you’re most likely to use routinely is SHA-1. Invented by the National Security Agency, it’s been around since 1995. Recently, though, there have been some pretty impressive cryptanalytic attacks against the algorithm. The best attack is barely on the edge of feasibility, and not effective against all applications of SHA-1. But there’s an old saying inside the NSA: “Attacks always get better; they never get worse.” It’s past time to abandon SHA-1.

There are near-term alternatives—a related algorithm called SHA-256 is the most obvious—but they’re all based on the family of hash functions first developed in 1992. We’ve learned a lot more about the topic in the past 15 years, and can certainly do better.

Why the National Institute of Standards and Technology, or NIST, though? Because it has exactly the experience and reputation we want. We were in the same position with encryption functions in 1997. We needed to replace the Data Encryption Standard, but it wasn’t obvious what should replace it. NIST decided to orchestrate a worldwide competition for a new encryption algorithm. There were 15 submissions from 10 countries—I was part of the group that submitted Twofish—and after four years of analysis and cryptanalysis, NIST chose the algorithm Rijndael to become the Advanced Encryption Standard (.pdf), or AES.

The AES competition was the most fun I’ve ever had in cryptography. Think of it as a giant cryptographic demolition derby: A bunch of us put our best work into the ring, and then we beat on each other until there was only one standing. It was really more academic and structured than that, but the process stimulated a lot of research in block-cipher design and cryptanalysis. I personally learned an enormous amount about those topics from the AES competition, and we as a community benefited immeasurably.

NIST did a great job managing the AES process, so it’s the perfect choice to do the same thing with hash functions. And it’s doing just that (.pdf). Last year and the year before, NIST sponsored two workshops to discuss the requirements for a new hash function, and last month it announced a competition to choose a replacement for SHA-1. Submissions will be due in fall 2008, and a single standard is scheduled to be chosen by the end of 2011.

Yes, this is a reasonable schedule. Designing a secure hash function seems harder than designing a secure encryption algorithm, although we don’t know whether this is inherently true of the mathematics or simply a result of our imperfect knowledge. Producing a new secure hash standard is going to take a while. Luckily, we have an interim solution in SHA-256.

Now, if you’ll excuse me, the Twofish team needs to reconstitute and get to work on an Advanced Hash Standard submission.

This essay originally appeared on Wired.com.

EDITED TO ADD (2/8): Every time I write about one-way hash functions, I get responses from people claiming they can’t possibly be secure because an infinite number of texts hash to the same short (160-bit, in the case of SHA-1) hash value. Yes, of course an infinite number of texts hash to the same value; that’s the way the function works. But the odds of it happening naturally are less than the odds of all the air molecules bunching up in the corner of the room and suffocating you, and you can’t force it to happen either. Right now, several groups are trying to implement Xiaoyun Wang’s attack against SHA-1. I predict one of them will find two texts that hash to the same value this year—it will demonstrate that the hash function is broken and be really big news.

Posted on February 8, 2007 at 9:07 AM • View Comments

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Sidebar photo of Bruce Schneier by Joe MacInnis.