sdevlin

7 ms·

31.
by sdevlin 11y ago
https://tobtu.com/decryptocat.php
32.
Dear Cryptocat Users(crypto.cat)
122 points by sdevlin 11y ago|53 comments
33.
by sdevlin 11y ago
I think e needs to be coprime with phi(N) rather than N itself. This is so you can find d = e^-1 mod phi(N), which would otherwise not exist. Of course, if e shares a factor with N, you have bigger problems.
34.
by sdevlin 11y ago
Why did you need to write an implementation of Mersenne Twister?
35.
by sdevlin 11y ago
Some of these issues are orthogonal. You're correct that the ring of integers mod n with n composite will have small multiplicative subgroups. But so will the integers mod p with p prime. At the very least, 1 and p-1 will always have o
36.
by sdevlin 11y ago
Cure53's report details a complete bypass of WebSign as implemented, as well as stern warnings against relying on a non-security feature for security.
37.
by sdevlin 11y ago
Double Fine's Devs Play series might be interesting to you. The first season includes a bunch of videos featuring John Romero talking about Doom. Here's a playlist: https://www.youtube.com/playlist?list=PLIhLvue17S
38.
by sdevlin 11y ago
It depends on how P and Q are generated. The NIST document specifying Dual EC offers default values for each curve. P is the usual base point for the curve; an arbitrary point Q is provided without justification or details of its generation
39.
by sdevlin 11y ago
AES (and other symmetric ciphers) are vulnerable to Grover's algorithm ( https://en.wikipedia.org/wiki/Grover%27s_algorithm ), which effectively cuts key sizes in half. AES-128 would be reduced to 64-bit security. T
40.
by sdevlin 11y ago
If you're looking for more crypto challenges, we've just released set 8 of Cryptopals. It's kind of a "soft" release; it's not on the site yet. Mail set8.cryptopals@gmail.com with subject "Crazy Flamboyant
41.
by sdevlin 11y ago
It happens. :) I agree, POODLE is a close analog.
42.
by sdevlin 11y ago
BEAST and CRIME are both chosen-plaintext attacks. They don't rely on the improper MAC composition in TLS CBC. Lucky13 and POODLE are the chosen-ciphertext attacks. EDIT: Some more details: BEAST takes advantage of predictable IVs in S
43.
by sdevlin 11y ago
Theoretical attacks have a way of turning into weaponized exploits. For example, check out https://www.openssl.org/~bodo/tls-cbc.txt . This is a document published by Bodo Moeller in the early 2000s that details multipl
44.
by sdevlin 11y ago
Thanks!
45.
by sdevlin 11y ago
Is MVC the default ASP.NET workflow now? Is it the only workflow? Are Web Forms still supported?
46.
by sdevlin 11y ago
If that is true, the author should avoid words like "secure" and "unbreakable".
47.
by sdevlin 11y ago
> With this (and your computer) you can secure a message with a password in a way that's unbreakable. I can't break it, your government can't break it, other people's governments can't break it. Secure. Argh. No.
48.
by sdevlin 11y ago
TweetNaCl is a C library.
49.
by sdevlin 11y ago
Dual EC specifies two standard curve points. The "kleptographic" back door is the relationship between them, i.e. the knowledge of d in the equation P = dQ. This hidden relationship was apparent to cryptographers pretty quickly, s
50.
by sdevlin 11y ago
The paper or the post? I think the paper is maybe slightly dismissive, closer to neutral: "it is conceivable the NSA has found ...". The post seems more enthusiastic: "the most intriguing hypotheses in the paper" "B
51.
by sdevlin 11y ago
The paper discusses the quantum case: > However, it will require major advances in physics and engineering before quantum computing can scale significantly. When that happens, of course P-256 and P-384 will fall first. But, as the head o
52.
by sdevlin 11y ago
The post talks about hypothetical improvements in non-QC approaches to the ECDLP.
53.
by sdevlin 11y ago
Yes. It's usually not even accessible through the hash function's exposed interface.
54.
by sdevlin 11y ago
The post you're responding to says explicitly in the first sentence that these are breaking changes.
55.
by sdevlin 11y ago
Isn't PBKDF2 in the stdlib as hashlib.pbkdf2_hmac?
56.
The Mathematical Hacker(evanmiller.org)
2 points by sdevlin 11y ago|0 comments
57.
by sdevlin 11y ago
I don't know if I would characterize NaCl as "enormous". TweetNaCl is literally two files. Libsodium has a bigger footprint, but it also seems to have bindings for pretty much every language. I would think it's pretty ea
58.
by sdevlin 11y ago
This is unfortunately sort of common. Java's crypto package exposes a similar interface.
59.
by sdevlin 11y ago
The major complaint against AES is that it is very difficult to implement in a data-independent way without hardware support. Bernstein has done some research on this ( http://cr.yp.to/antiforgery/cachetiming-20050414.pd
60.
by sdevlin 11y ago
The authentication mode for GCM is sort of fragile. While nonce reuse is always bad, it's particularly disastrous in GCM in that it immediately leaks the authentication key. Similarly, using GCM with a truncated authentication tag make

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