Entries Tagged "cryptography"

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NSA Watch

Three things.

U.S. Patent #6,947,978:

Method for geolocating logical network addresses

Abstract: Method for geolocating logical network addresses on electronically switched dynamic communications networks, such as the Internet, using the time latency of communications to and from the logical network address to determine its location. Minimum round-trip communications latency is measured between numerous stations on the network and known network addressed equipment to form a network latency topology map. Minimum round-trip communications latency is also measured between the stations and the logical network address to be geolocated. The resulting set of minimum round-trip communications latencies is then correlated with the network latency topology map to determine the location of the network address to be geolocated.

“Fact Sheet NSA Suite B Cryptography“:

The entire suite of cryptographic algorithms is intended to protect both classified and unclassified national security systems and information. Because Suite B is a also subset of the cryptographic algorithms approved by the National Institute of Standards, Suite B is also suitable for use throughout government. NSA’s goal in presenting Suite B is to provide industry with a common set of cryptographic algorithms that they can use to create products that meet the needs of the widest range of US Government (USG) needs.

“The Case for Elliptic Curve Cryptography“:

Elliptic Curve Cryptography provides greater security and more efficient performance than the first generation public key techniques (RSA and Diffie-Hellman) now in use. As vendors look to upgrade their systems they should seriously consider the elliptic curve alternative for the computational and bandwidth advantages they offer at comparable security.

Posted on September 30, 2005 at 7:31 AM • View Comments

The Doghouse: CryptIt

It’s been far too long since I’ve had one of these.

CryptIt looks like just another one-time pad snake-oil product:

Most file encryptions use methods that mathematically hash a password to a much larger number and rely on the time taken to reverse this process to prevent unauthorised decryption. Providing the key length is 128 bits or greater this method works well for most purposes, but since these methods do have predictable patterns they can be cracked. CPUs are increasing in speed at a fast rate and these encryption methods can be beaten given luck and/or enough computers. XorIt uses the XOR encryption method (also known as Vernam encryption) that can have keys the same size as the file to be encrypted. Thus, if you are encrypting a 5MB file, then you can have what is in effect a 40 Million bit key! This is virtually unbreakable by any computer, especially when you consider that the file must also be checked with each combination to see if it is decrypted. To put is another way, since XorIt gives no pass/fail results brute force methods are difficult to implement. In fact, if you use a good key file that is the same size or larger than the source and do not reuse the key file then it it impossible to decrypt the file, no matter how fast the computer is. Furthermore, the key file can be anything – a program, a swap file, an image of your cat or even a music file.

Amazingly enough, some people still believe in this sort of nonsense. Before defending them, please read my essay on snake oil.

Posted on September 28, 2005 at 1:25 PM •

New Cryptanalytic Results Against SHA-1

Xiaoyun Wang, one of the team of Chinese cryptographers that successfully broke SHA-0 and SHA-1, along with Andrew Yao and Frances Yao, announced new results against SHA-1 yesterday at Crypto’s rump session. (Actually, Adi Shamir announced the results in their name, since she and her student did not receive U.S. visas in time to attend the conference.)

Shamir presented few details—and there’s no paper—but the time complexity of the new attack is 263. (Their previous result was 269; brute force is 280.) He did say that he expected Wang and her students to improve this result over the next few months. The modifications to their published attack are still new, and more improvements are likely over the next several months. There is no reason to believe that 263 is anything like a lower limit.

But an attack that’s faster than 264 is a significant milestone. We’ve already done massive computations with complexity 264. Now that the SHA-1 collision search is squarely in the realm of feasibility, some research group will try to implement it. Writing working software will both uncover hidden problems with the attack, and illuminate hidden improvements. And while a paper describing an attack against SHA-1 is damaging, software that produces actual collisions is even more so.

The story of SHA-1 is not over. Again, I repeat the saying I’ve heard comes from inside the NSA: “Attacks always get better; they never get worse.”

Meanwhile, NIST is holding a workshop in late October to discuss what the security community should do now. The NIST Hash Function Workshop should be interesting, indeed. (Here is one paper that examines the effect of these attacks on S/MIME, TLS, and IPsec.)

EDITED TO ADD: Here are Xiaoyun Wang’s two papers from Crypto this week: “Efficient Collision Search Attacks on SHA-0” and “Finding Collisions in the Full SHA-1Collision Search Attacks on SHA1.” And here are the rest of her papers.

Posted on August 17, 2005 at 2:06 PM • View Comments

Chinese Cryptographers Denied U.S. Visas

Chinese cryptographer Xiaoyun Wang, the woman who broke SHA-1 last year, was unable to attend the Crypto conference to present her paper on Monday. The U.S. government didn’t give her a visa in time:

On Monday, she was scheduled to explain her discovery in a keynote address to an international group of researchers meeting in California.

But a stand-in had to take her place, because she was not able to enter the country. Indeed, only one of nine Chinese researchers who sought to enter the country for the conference received a visa in time to attend.

Sadly, this is now common:

Although none of the scientists were officially denied visas by the United States Consulate, officials at the State Department and National Academy of Sciences said this week that the situation was not uncommon.

Lengthy delays in issuing visas are now routine, they said, particularly for those involved in sensitive scientific and technical fields.

These delays can make it impossible for some foreign researchers to attend U.S. conferences. There are researchers who need to have their paper accepted before they can apply for a visa. But the paper review and selection process, done by the program committee in the months before the conference, doesn’t finish early enough. Conferences can move the submission and selection deadlines earlier, but that just makes the conference less current.

In Wang’s case, she applied for her visa in early July. So did her student. Dingyi Pei, another Chinese researcher who is organizing Asiacrypt this year, applied for his in early June. (I don’t know about the others.) Wang has not received her visa, and Pei got his just yesterday.

This kind of thing hurts cryptography, and hurts national security. The visa restrictions were designed to protect American advanced technologies from foreigners, but in this case they’re having the opposite effect. We are all more secure because there is a vibrant cryptography research community in the U.S. and the world. By prohibiting Chinese cryptographers from attending U.S. conferences, we’re only hurting ourselves.

NIST is sponsoring a workshop on hash functions (sadly, it’s being referred to as a “hash bash”) in October. I hope Wang gets a visa for that.

Posted on August 17, 2005 at 11:53 AM • View Comments

Cryptographically-Secured Murder Confession

From the Associated Press:

Joseph Duncan III is a computer expert who bragged online, days before authorities believe he killed three people in Idaho, about a tell-all journal that would not be accessed for decades, authorities say.

Duncan, 42, a convicted sex offender, figured technology would catch up in 30 years, “and then the world will know who I really was, and what I really did, and what I really thought,” he wrote May 13.

Police seized Duncan’s computer equipment from his Fargo apartment last August, when they were looking for evidence in a Detroit Lakes, Minn., child molestation case.

At least one compact disc and a part of his hard drive were encrypted well enough that one of the region’s top computer forensic specialists could not access it, The Forum reported Monday.

This is the kind of story that the government likes to use to illustrate the dangers of encryption. How can we allow people to use strong encryption, they ask, if it means not being able to convict monsters like Duncan?

But how is this different than Duncan speaking the confession when no one was able to hear? Or writing it down and hiding it where no one could ever find it? Or not saying anything at all? If the police can’t convict him without this confession—which we only have his word for as existing—then maybe he’s innocent?

Technologies have good and bad uses. Encryption, telephones, cars: they’re all used by both honest citizens and by criminals. For almost all technologies, the good far outweighs the bad. Banning a technology because the bad guys use it, denying everyone else the beneficial uses of that technology, is almost always a bad security trade-off.

EDITED TO ADD: Looking at the details of the encryption, it’s certainly possible that the authorities will break the diary. It probably depends on how random a key Duncan chose, although possibly on whether or not there’s an implementation error in the cryptographic software. If I had more details, I could speculate further.

Posted on August 15, 2005 at 2:17 PM • View Comments

U.S. Crypto Export Controls

Rules on exporting cryptography outside the United States have been renewed:

President Bush this week declared a national emergency based on an “extraordinary threat to the national security.”

This might sound like a code-red, call-out-the-national-guard, we-lost-a-suitcase-nuke type of alarm, but in reality it’s just a bureaucratic way of ensuring that the Feds can continue to control the export of things like computer hardware and encryption products.

And it happens every year or so.

If Bush didn’t sign that “national emergency” paperwork, then the Commerce Department’s Bureau of Industry and Security would lose some of its regulatory power. That’s because Congress never extended the Export Administration Act after it lapsed (it’s complicated).

President Clinton did the same thing. Here’s a longer version of his “national emergency” executive order from 1994.

As a side note, encryption export rules have been dramatically relaxed since the oppressive early days of Janet “Evil PCs” Reno, Al “Clipper Chip” Gore, and Louis “ban crypto” Freeh. But they still exist. Here’s a summary.

To be honest, I don’t know what the rules are these days. I think there is a blanket exemption for mass-market software products, but I’m not sure. I haven’t a clue what the hardware requirements are. But certainly something is working right; we’re seeing more strong encryption in more software—and not just encryption software.

Posted on August 5, 2005 at 7:17 AM • View Comments

Plagiarism and Academia: Personal Experience

A paper published in the December 2004 issue of the SIGCSE Bulletin, “Cryptanalysis of some encryption/cipher schemes using related key attack,” by Khawaja Amer Hayat, Umar Waqar Anis, and S. Tauseef-ur-Rehman, is the same as a paper that John Kelsey, David Wagner, and I published in 1997.

It’s clearly plagiarism. Sentences have been reworded or summarized a bit and many typos have been introduced, but otherwise it’s the same paper. It’s copied, with the same section, paragraph, and sentence structure—right down to the same mathematical variable names. It has the same quirks in the way references are cited. And so on.

We wrote two papers on the topic; this is the second. They don’t list either of our papers in their bibliography. They do have a lurking reference to “[KSW96]” (the first of our two papers) in the body of their introduction and design principles, presumably copied from our text; but a full citation for “[KSW96]” isn’t in their bibliography. Perhaps they were worried that one of the referees would read the papers listed in their bibliography, and notice the plagiarism.

The three authors are from the International Islamic University in Islamabad, Pakistan. The third author, S. Tauseef-Ur-Rehman, is a department head (and faculty member) in the Telecommunications Engineering Department at this Pakistani institution. If you believe his story—which is probably correct—he had nothing to do with the research, but just appended his name to a paper by two of his students. (This is not unusual; it happens all the time in universities all over the world.) But that doesn’t get him off the hook. He’s still responsible for anything he puts his name on.

And we’re not the only ones. The same three authors plagiarized this paper by French cryptographer Serge Vaudenay and others.

I wrote to the editor of the SIGCSE Bulletin, who removed the paper from their website and demanded official letters of admission and apology. (The apologies are at the bottom of this page.) They said that they would ban them from submitting again, but have since backpedaled. Mark Mandelbaum, Director of the Office of Publications at ACM, now says that ACM has no policy on plagiarism and that nothing additional will be done. I’ve also written to Springer-Verlag, the publisher of my original paper.

I don’t blame the journals for letting these papers through. I’ve refereed papers, and it’s pretty much impossible to verify that a piece of research is original. We’re largely self-policing.

Mostly, the system works. These three have been found out, and should be fired and/or expelled. Certainly ACM should ban them from submitting anything, and I am very surprised at their claim that they have no policy with regards to plagiarism. Academic plagiarism is serious enough to warrant that level of response. I don’t know if the system works in Pakistan, though. I hope it does. These people knew the risks when they did it. And then they did it again.

If I sound angry, I’m not. I’m more amused. I’ve heard of researchers from developing countries resorting to plagiarism to pad their CVs, but I’m surprised see it happen to me. I mean, really; if they were going to do this, wouldn’t it have been smarter to pick a more obscure author?

And it’s nice to know that our work is still considered relevant eight years later.

EDITED TO ADD: Another paper, “Analysis of Real-time Transport Protocol Security,” by Junaid Aslam, Saad Rafique and S. Tauseef-ur-Rehman”, has been plagiarized from this original: Real-time Transport Protocol (RTP) security,” by Ville Hallivuori.

EDITED TO ADD: Ron Boisvert, the Co-Chair of the ACM Publications Board, has said this:

1. ACM has always been a champion for high ethical standards among computing professionals. Respecting intellectual property rights is certainly a part of this, as is clearly reflected in the ACM Code of Ethics.

2. ACM has always acted quickly and decisively to deal with allegations of plagarism related to its publications, and remains committed to doing so in the future.

3. In the past, such incidents of plagarism were rare. However, in recent years the number of such incidents has grown considerably. As a result, the ACM Publications Board has recently begun work to develop a more explicit policy on plagarism. In doing so we hope to lay out (a) what constitutes plagarism, as well as various levels of plagarism, (b) ACM procedures for handling allegations of plagarism, and (c) specific penalties which will be leveled against those found to have committed plagarism at each of the identified levels. When this new “policy” is in place, we hope to widely publicize it in order to draw increased attention to this growing problem.

EDITED TO ADD: There’s a news story with some new developments.

EDITED TO ADD: Over the past couple of weeks, I have been getting repeated e-mails from people, presumably faculty and administrators of the International Islamic University, to close comments in this blog entry. The justification usually given is that there is an official investigation underway so there’s no longer any reason for comments, or that Tauseef has been fired so there’s no longer any reason for comments, or that the comments are harmful to the reputation of the university or the country.

I have responded that I will not close comments on this blog entry. I have, and will continue to, delete posts that are incoherent or hostile (there have been examples of both).

Blog comments are anonymous. There is no way for me to verify the identity of posters, and I don’t. I have, and will continue to, remove any posts purporting to come from a person it does not come, but generally the only way I can figure that out is if the real person e-mails me and asks.

Otherwise, consider this a forum for anonymous free speech. The comments here are unvetted and unverified. They might be true, and they might be false. Readers are expected to understand that, and I believe for the most part they do.

In the United States, we have a saying that the antidote for bad speech is more speech. I invite anyone who disagrees with the comments on the page to post their own opinions.

Posted on August 1, 2005 at 6:07 AM • View Comments

Seagate's Full Disk Encryption

Seagate has introduced a hard drive with full-disk encryption.

The 2.5-inch drive offers full encryption of all data directly on the drive through a software key that resides on a portion of the disk nobody but the user can access. Every piece of data that crosses the interface encrypted without any intervention by the user, said Brian Dexheimer, executive vice president for global sales and marketing at the Scotts Valley, Calif.-based company.

Here’s the press release, and here’s the product spec sheet. Ignore the “TDEA 192” nonsense. It’s a typo; the product uses triple-DES, and the follow-on product will use AES.

Posted on June 27, 2005 at 7:24 AM • View Comments

SHA Cryptanalysis Paper Online

In February, I wrote about a group of Chinese researchers who broke the SHA-1 hash function. That posting was based on short notice from the researchers. Since then, many people have written me asking about the research and the actual paper, some questioning the validity of the research because of the lack of documentation.

The paper did exist; I saw a copy. They will present it at the Crypto conference in August. I believe they didn’t post it because Crypto requires that submitted papers not be previously published, and they misunderstood that to mean that it couldn’t be widely distributed in any way.

Now there’s a copy of the paper on the web. You can read “Finding Collisions in the Full SHA-1,” by Xiaoyun Wang, Yiqun Lisa Yin, and Hongbo Yu, here.

Posted on June 24, 2005 at 12:46 PM • View Comments

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Sidebar photo of Bruce Schneier by Joe MacInnis.