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NSA, NIST, and post-quantum crypto: my second lawsuit against the US government
141–150 of 494 posts
Re: NSA, NIST, and post-quantum crypto: my second lawsuit against the US government
#142Earlier quoted context omitted.
> "NSA credited tweaks to DES can be understood as ensuring that a weakened DES stayed deployed longer which was to their advantage. They clearly explain this in the history quoted by the author" I'm not sure I buy that this follows, wouldn't the weakened key size also make people not want to deploy it given that known weakness? To me it reads more that some people wanted a weak key so NSA could still break it, but o…
It follows: entire industries were required to deploy DES and the goal was to create one thing that was “strong enough” to narrow the field. Read the blog post carefully about the role of NBS, IBM, and NSA in the development of DES. It’s hard to accept because the implications are upsetting and profound. The evidence is clear and convincing. Lots of people try to muddy the waters, don’t help them please.
They had a privately known way to weaken DES that effectively shortens the key length. They could have pretended to allow a longer key length while secretly retaining their privately known attack that lets them shorten it (without also acting to strengthen DES against it). They knew this in the 70s 20 years before it would become publicly known. They actively strengthened DES against this while not revealing the exploit. Doing this secretly doesn't narrow the field (doing it publicly might have), it's also inconsistent with their argument for short keys.
I read the blog post and I've read a lot about the history of this - what you're saying isn't really convincing. Often people I mostly agree with, maybe 90% just take it to the extreme where everything must fit their world view 100%. Rarely imo is that the case, often reality is more mixed.
If they’re related maybe they wanted DES to be strong so they could use it, but wanted the public to only have access to short keys so they could also break the public's use of it. Still, it's interesting they didn't leave in a weakness they could exploit secretly despite a longer key size.
edited for clarity
Re: NSA, NIST, and post-quantum crypto: my second lawsuit against the US government
#143side question : I've only recently started to digg a bit deeper into crypto algorithms ( looking into various types of curves etc), and it gave me the uneasing feeling that the whole industry is relying on the expertise of only a handful of guys to actually ensure that crypto schemes used today are really working. Am i wrong ? are there actually thousands and thousands of people with the expertise to actually proove…
There may be thousands of people in the entire world who understand cryptanalysis well enough to accurately judge the security of modern ciphers. Most aren't living or working in the U.S. It's very difficult to do better. The mathematics is complex and computer science hasn't achieved proofs of the hypotheses underlying cryptography. The best we can achieve is heuristic judgements about what the best possible attacks…
> The mathematics is complex and computer science hasn't achieved proofs of the hypotheses underlying cryptography.
No unconditional proofs (except for the OTP ofc), but there are quite a few conditional proofs. For example, it's possible to show that CBC is secure if the underlying block cipher is.
Re: NSA, NIST, and post-quantum crypto: my second lawsuit against the US government
#144Tangential question: while some FOIA requests do get stonewalled, I continue to be fascinated that they're honored in other cases. What exactly prevents the government from stonewalling practically every request that it doesn't like, until and unless it's ordered by a court to comply? Is there any sort of penalty for their noncompliance? Tangential to the tangent: is there any reason to believe FOIA won't be on the c…
Presumably most government employees are acting in good faith - why wouldn’t they fulfil a reasonable FOIA request? This is likely the result of some actors not acting in good faith, and so have no choice but to stonewall lest their intransigence be revealed.
All execs have to do is not staff the FOIA department, and requests get ignored. People generally prefer free time to doing paperwork, if boss allows.
Re: NSA, NIST, and post-quantum crypto: my second lawsuit against the US government
#145Why is the link in the URL http: not https: ? Irony?
If you spend all day making bagels do you go home and make bagels for dinner? It's a static text blog, not a bank
> It's a static text blog, not a bank
I want those delivered by https most, because http leaks the exact page I've visited, rather than just the domain.
Re: NSA, NIST, and post-quantum crypto: my second lawsuit against the US government
#146Earlier quoted context omitted.
Surely I'm misunderstanding, are you really advocating that people should roll their own encryption algorithms from scratch? As in, they should invent novel and secure algorithms in isolation? And this should happen.... at every major enterprise or software company in the world?
You are completely misunderstanding yes. I'm saying some standards body is appropriate for validating/vetting algorithms, and having a standards body advocate for known reasonable ones is... reasonable and desirable. That NIST has a history of being compromised by the NSA (and other standards bodies would likely similarly be a target), is a problem. But having everyone 'figure it out' on their own is even worse. 'han…
That makes much more sense. Thank you for the clarification.
Re: NSA, NIST, and post-quantum crypto: my second lawsuit against the US government
#147Earlier quoted context omitted.
Surely I'm misunderstanding, are you really advocating that people should roll their own encryption algorithms from scratch? As in, they should invent novel and secure algorithms in isolation? And this should happen.... at every major enterprise or software company in the world?
You are completely misunderstanding yes. I'm saying some standards body is appropriate for validating/vetting algorithms, and having a standards body advocate for known reasonable ones is... reasonable and desirable. That NIST has a history of being compromised by the NSA (and other standards bodies would likely similarly be a target), is a problem. But having everyone 'figure it out' on their own is even worse. 'han…
> That NIST has a history of being compromised by the NSA is a problem.
It's a disqualifying problem. If you go to a standards body to prevent yourself from making unintentional mistakes, and they have introduced intentional mistakes, any other reasonable option is better.
Re: NSA, NIST, and post-quantum crypto: my second lawsuit against the US government
#148djb has got to be the single biggest pain in the ass for the NSA and I love it.
Re: NSA, NIST, and post-quantum crypto: my second lawsuit against the US government
#149Perhaps the old advice (“never roll your own crypto”) should be reevaluated? If you’re creative enough, you could combine and apply existing algorithms in such ways that it would be very difficult to decrypt? Think 500 programmatic combinations (steps) of encryption applying different algorithms. Content encrypted in this way would require knowledge of the encryption sequence in order to execute the required steps in…
No, an important property of a secure cryptographic cipher is that it should be as close to a random permutation of the input as possible.
A "randomly assembled" cipher that just chains together different primitives without much thought is very unlikely to have that, which will mean that it will probably have "interesting" statistical properties that can be observed given enough plaintext/ciphertext pairs, and those can then be exploited in order to break it.
Re: NSA, NIST, and post-quantum crypto: my second lawsuit against the US government
#150Earlier quoted context omitted.
You are not accurately reflecting the history that is presented in the very blog post we are discussing. NSA made DES weaker for everyone by reducing the key size. IBM happily went along. The history of IBM is dark. NSA credited tweaks to DES can be understood as ensuring that a weakened DES stayed deployed longer which was to their advantage. They clearly explain this in the history quoted by the author: “Narrowing…
>IBM happily went along. The history of IBM is dark. Then, as of now, I'm confused why people expect these kinds of problems to be solved by corporations "doing the right thing" rather than demanding some kind of real legislative reform.
Is there a third option beyond government and corporations?