Cryptography Expert Sounds Alarm At Possible Math Hack

netbuzz writes "First we learn from Bruce Schneier that the NSA may have left itself a secret back door in an officially sanctioned cryptographic random-number generator. Now Adi Shamir is warning that a math error unknown to a chip makers but discovered by a tech-savvy terrorist could lead to serious consequences, too. Remember the Intel blunder of 1996? 'Mr. Shamir wrote that if an intelligence organization discovered a math error in a widely used chip, then security software on a PC with that chip could be "trivially broken with a single chosen message." Executing the attack would require only knowledge of the math flaw and the ability to send a "poisoned" encrypted message to a protected computer, he wrote. It would then be possible to compute the value of the secret key used by the targeted system.'"

Comments

The NSA

[proudfoot]

The problem with backdoors, is that noone can guarantee who uses them. While it allows for (possibly) justified surveillance by our government, it also allows for it by others.

The United States, or the NSA, doesn't have all the world's best cryptographers. Russia, China, etc, other nations have excellent skill in these endeavors. Ironically, by trying to protect the nation, the NSA runs the risk of opening us up to foreign espionage.

Original article

[sk19842]

TFA is just a summary of an article yesterday in the NYT: http://www.nytimes.com/2007/11/17/technology/17code.html?ref=technology

how many encryption schemes us floating point?

[Kuciwalker]

It seems to me that the most likely source of a math error is in the floating point unit, since floating point math is far more complex than integer math. I've always understood that most crypto is based on integer math, both because it's based on number theory and because floating point math isn't exact. Doesn't that make this sort of exploit extremely unlikely?

Re:First Post?

[Anonymous Coward]

Um, no. "The terrorists" (a pretty vauge term but I'm assuming you mean those from middle eastern countries by the way you're wording your statement) don't give a rat's ass how we live, whether we have free elections or live with an oppressive government nor do they really care much about how we go about our daily lives, etc, etc. The terrorists wants the US and western countries to stop fucking around in their countries- supporting/installing dictatorships that happen to ally with our interests while bombing and invading countries that we don't like, setting up permanent military bases and just generally exerting our will on them. After a few generations of having western powers screw with their countries and lives it should be little wonder we're not well liked.

Of course, if you were refering to China or someone else then that might be a different story (but again, the wording sounded like someone regurgitating the drivel that gets thrown out by politicians and pundits in the mainstream media).

No.

[Valdrax]

Terrorists want us to stop screwing around in the Middle East and Central Asia -- specifically they want us to stop supporting Israel and to stop propping up various dictatorships in countries where there'd be a good chance of overthrowing the government and creating a theocracy.

They don't give a flying f--- about "our freedoms" except where they think that shows we are "morally corrupt." Islamic militants are under no illusions that they're going to change our culture any time soon, though. They've got bigger fish to fry back home trying to establish a power block.

How we govern ourselves beyond our foreign policy is utterly unimportant to their larger goals.

Re:No.

[Anonymous Coward]

Those people are an absolutely tiny minority and can be dealt with sensibly. The majority of people would just like us to stop meddling.

Stop pissing people off and the nut-jobs who do want us removed will have lost their primary recruitment method.

Re:No.

[Valdrax]

Define Terrorists please. If you're talking about Al-Queda, you're wrong. This group hates democracy as it goes against Sharia law to the most extreme. Anything governed outside this religious foundation is seen as an act of Hubris and thus punishable by death in the eyes of Allah (Arabic word for God).

Yeah, but al-Qaeda doesn't care about our democracy. And seeing us turn into a secular or Christian dictatorship in no way helps further their goals. The more crazy fascist our government becomes, ironically, the less accepting of Islamic fundamentalism it becomes even as it becomes equally repressive. If anything, it's against their long term goals to see us harder ourselves against them.

Next time, educate yourself about our sworn western enemies before justifying their cause. Bluntly put, I don't give a damn about their cause. These people need to die like the parasites they are on humanity.

What does explaining their motivations have to do with justifying them? You seem to be the sort of reactionary type that associates any attempt to understand your enemy with accepting them and capitulating to them.

Geez, it's no wonder you people are losing the War on Terrorism for us.

NSA "Suite A" is the real problem.

[Kadin2048]

Which is why I, for one, doubt that the back door was intentional. The approval that NSA gives is primarily for use by the US government itself, and most of the obstacles that NSA faces in spying on our own government are bureaucratic ones, not technical ones. I agree, for what it's worth (not much, but we're mostly all armchair generals here, why not join in the fun?).

The flaw seems too obvious to really have been something illicit. If it was an attempt at a backdoor, it was pretty stupid. And it was a weird/improbable way to create a backdoor -- it was PRNG, not really a cryptographic function per se, and while knowing its output could help you break a system, it wouldn't guarantee it. The people at the NSA had to know it would be combed over.

But the fact that it seems to be incompetence rather than malice doesn't make me feel a whole lot better. There are still a bunch of secret-algorithm ciphers around and in use (and which the government, in its infinite wisdom, treats as more secure than the openly-reviewed ones), that the NSA is basically the only organization that has any access to. If they could miss such a trivial flaw in a PRNG that they knew was going to go out for public scrutiny, what could they have let slip by in a cryptographic function that was supposed to be a state secret?