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Aug
24
comment How does compression before encryption leak info about the input?
"I'm pretty sure adding an "evil" chunk to a JPEG image won't leak the "good" part." - I don't know how you could possibly know that. Anyway, I believe my answer answers that question that was asked.
Aug
20
reviewed Approve suggested edit on S-box with differential uniformity = 2
Aug
19
accepted Why is TLS susceptible to protocol downgrade attacks?
Aug
19
comment Simple proof that shows AES is not a uniform permutation on any n-bit string?
@Gilles, assuming the author means that it is uniformly distributed on the set of all permutations (when the key is randomly chosen)... the other thread proves that AES does not have this property. Of course, Dimitry's answer is an excellent answer, too.
Aug
19
comment Simple proof that shows AES is not a uniform permutation on any n-bit string?
possible duplicate of Block cipher and parity of permutation
Aug
15
comment Are there any cryptographic flaws in my webhook signing process?
@JessieA.Morris, for what it's worth, there are multiple different ways one can do TLS with client certs; they don't all require having a single trusted CA. But I've said my piece.
Aug
15
comment Are there any cryptographic flaws in my webhook signing process?
@JessieA.Morris, you're still creating your own mini-protocol. My advice stands. P.S. I'm not certain you mean by "work". Your statement that client-side certs introduce more work doesn't sound right to me. If you mean development cost, I don't agree. If you mean computation time, then I suggest you benchmark it, but I bet you'll find that TLS client certs are no worse than anything else that involves a client-side signature. Either way, if TLS+client certs doesn't meet your needs, you should clarify the question by being more precise about requirements.
Aug
15
answered Are there any cryptographic flaws in my webhook signing process?
Aug
15
reviewed Leave Open $(k, n)$ threshold secret sharing to $(k+k', n + n')$ without reissuing all shares
Aug
15
reviewed Close I am new to Cryptography and I wonder if one can Suggest me Beginner Projects
Aug
15
comment Are there any cryptographic flaws in my webhook signing process?
Is there a reason you aren't just using client certificates? They were designed for solving this problem. The TLS folks thought a lot about the security challenges, so you wouldn't have to.
Aug
4
answered Secure MultiParty Computation with secret inputs for secret outputs
Aug
4
awarded  Yearling
Aug
2
comment run length testing
This question looks off-topic to me. The site is for questions about cryptography (see here); your question does not appear to fit the fall within the scope of the site.
Aug
2
comment Theoretical attack on RSA
What's your question, specifically? This is not the place for open-ended questions ("Please leave opinions on that") -- this is for specific, answerable questions. In any case, this is a duplicate of the other question that Ricky Demer identifies.
Jul
31
comment Questions on FHE over the Integers - the question modified!
@JongHyunKim, please don't use comments to ask a new question. Comments should only be used to help the author of the answer improve their answer. (This is not a discussion forum; see the faq for more details on how to use this site.)
Jul
30
awarded  Good Answer
Jul
29
revised How can rainbow tables be used for a dictionary attack?
Incorporate the complexity of these attacks, per a comment from Thomas Pornin.
Jul
29
comment Is it secure to use Diffie-Hellman key agreement to generate a nonce?
@YoavR., it sounds like you are using terminology in a non-standard manner. I don't know what you mean by "this is Nonce - by design it uses counter". I don't understand why you think a MAC "doesn't fit"; your explanation didn't make any sense to me. Again, if you want to receive help, edit your question to specify the security goals you are trying to achieve, what your requirements are, what mechanisms you have considered, what ones you have rejected, and why. I have to say this sounds like an instance of an XY problem.
Jul
29
comment Is it secure to use Diffie-Hellman key agreement to generate a nonce?
@YoavR., no, that is not correct. The purpose of an IV is not to prevent replays. The purpose of an IV is to provide confidentiality (to ensure that if the sender encrypts the same message twice, this won't be apparent to an eavesdropper). If you want to prevent replays, you should use a different mechanism: e.g., sequence numbers and a MAC. Please edit your question to describe what you are trying to achieve, as it looks very much like you are making some (incorrect) assumptions about the best way to achieve it.