2,422 reputation
21134
bio website stackexchange.com/users/…
location
age
visits member for 3 years, 2 months
seen 19 hours ago

Moderator♦ pro tempore on French Language, Computer Science and Software Recommendations. I'm also a unix amateur, and a developer with a computer science background and security leanings by trade.

Interested in embedded systems? Join the Embedded Programming and Design proposal!

Programmeurs francophones : participez à Stack Overflow en français.

Avatar picture slightly adapted from a photo by Luridiformis (Zonda Grattus).


Oct
17
comment How do you test randomness?
@otus I disagree about your proposed duplicate: testing the randomess of a CSPRNG output is completely different from testing the randomness of an entropy source. For one thing, the former is just about useless, the latter is useful.
Oct
17
comment How can I break this cipher?
@jayann If you're curious, this is from an exam. The part that Nick extracted into his SE questions doesn't make sense on its own. By the way, Nick, do not post the same question on multiple sites.
Oct
15
comment How would I write my own asymmetric encryption algorithm (not RSA, DES etc)?
Read a book. This isn't something that can be answered in a few paragraphs.
Oct
2
comment What is the translation for “hash” in french?
This question is off-topic because it is about French. Given that it is trivially answered by checking the translation of the Wikipedia article, it would not be accepted on French Language (but non-trivial questions on technical terminology would be).
Oct
1
comment How can I extract a X.509 DER certificate from a byte[]?
This question appears to be off-topic because it is purely about programming, with only indirect relevance of cryptography. It should be asked on Stack Overflow.
Sep
12
comment How Could the Music Industry Go About Implementing Crypto?
A method similar to what? Along what lines? Please make your question self-contained apart from general knowledge about the subject. Don't assume that people have read a specific book or watched a specific video or the like.
Sep
12
comment Data I/O operations for encrypted files
Dmcrypt encrypts per block, not per file (it doesn't even know what a file is).
Sep
11
comment How can I know when a file was signed?
@KrNeki You can do that with a digital notary if at least some part of the notary is running in a tamper-resistant device in your possession.
Sep
11
comment How can I know when a file was signed?
@KrNeki Any solution between point 1 and point 2 requires that you authenticate to the notary, so that the notary knows that it is indeed you who did the signing. You can't authenticate by signing a message, but you could provide a second authentication factor such as biometrics. This is logistically demanding since this essentially requires physical presence with the notary.
Sep
11
comment How can one generate pairs/triplets/…/n-ary MD5 collisions
@JohnDeters No, finding collisions with no constraint on the messages is very different from finding collisions where one of the messages is imposed.
Sep
10
comment Data I/O operations for encrypted files
Why not use the Linux's block device-level encryption (dmcrypt)? Have you investigated ecryptfs?
Sep
3
comment AES-ECB as an authentication mechanism
Similar question on Information Security (not with ECB, but with a slightly more complex mode that exhibits a similar problem)
Sep
2
comment How Proof all Subgroup point of prime order elliptic curve have prime order [#G=#E]?
Since you seem to have understood the question, could you translate it into English? I can't work out how to parse “Subgroup point of prime order elliptic curve”.
Aug
25
comment What are the advantages of TOTP over HOTP?
This answer makes no sense in relation with the question. TOTP and HOTP are intended as a form of authentication (usually as a what-you-have factor as the values are read off a token). They have nothing to do with other aspects of establishing a secure channel.
Aug
23
comment Seemingly simple decryption question
Although this question is possibly about breaking cryptography, there is too little information to answer it from a cryptographic perspective. It could be a valid question about reverse engineering in general, for which a potential venue would be Reverse Engineering.
Aug
19
comment Simple proof that shows AES is not a uniform permutation on any n-bit string?
@D.W. While this thread is surely related, I don't understand how it answers this question. What does it mean for a specific permutation to be uniform anyway?
Aug
15
comment Advantages of 64-bit CPU smartphone
Actually, there is probably a technical basis for that statement: ARMv8 processors introduce both 64-bit general registers and hardware acceleration for AES and SHA-{1,2}. But the two are not correlated.
Aug
12
comment Security issues of a MAC-then-Encrypt-then-MAC approach?
Background: Should we MAC-then-encrypt or encrypt-then-MAC? Could you comment on why or when one would want plaintext integrity in a way that isn't satisfied by ciphertext integrity?
Jul
28
comment Can you help me understand this “Message Modification by Meet-in-the-Middle” related to Tiger Hash?
Have you read the meet-in-the-middle article on Wikipedia?
Jul
25
comment Are there any Javascript CSPRNGs?
Your question is not clear: you say you want a CSPRNG, and then you talk about an entropy source. Do you need a CSRNG (unpredictable, i.e. at least seeded with a sufficient entropy source), or a CSPRNG (i.e. deterministic, but predictable only by knowing the secret seed)?