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Apr
6
reviewed Reject Wrong Test Vector for HKDF with HMAC-SHA256
Apr
6
comment Wrong Test Vector for HKDF with HMAC-SHA256
This question appears to be off-topic because it is about software development (try StackOverflow).
Apr
5
awarded  Favorite Question
Apr
5
comment Should we MAC-then-encrypt or encrypt-then-MAC?
I edited the answer to more clearly express the point Josef was trying to make. Personally, I think the answer is fine (I upvoted it).
Apr
5
revised Random oracle model proofs and programmability
Improve the title & question a bit.
Apr
5
reviewed Reject Random oracle model proofs and programmability
Apr
4
revised Should we MAC-then-encrypt or encrypt-then-MAC?
added 448 characters in body
Apr
3
answered Key-dependent encryption in TAHOE-LAFS
Apr
3
comment Key-dependent encryption in TAHOE-LAFS
What is ENC, specifically? How is it instantiated?
Apr
2
answered How do I create a short signature? (e.g. less than 100 bytes)
Apr
2
comment Combining multiple symmetric encryption algorithms - implications?
@StephenTouset, oh, right, thank you! Boy that was a dumb thing to write. :-) I appreciate the comment.
Apr
2
revised Combining multiple symmetric encryption algorithms - implications?
Address a typo spotted by Stephen Touset.
Mar
31
answered Operation sequence authentication shared storage
Mar
31
comment Can a commutative block cipher be indistinguishable from a random permutation, for fixed key?
@fgrieu, yes, maybe posting a separate question would be best. When you do, can you spell out how we choose a random set of permutations with the commutativity property? Is that notion uniquely defined?
Mar
30
comment HKDF vs TLS PRF. Which of the one is better?
Better, in what sense? More secure, in what sense? For what purposes? Under what threat model? This question is too vague as it stands; I suggest you edit it to make it more specific.
Mar
29
comment Is Porticor's “homomorphic” key encryption something that can really be done or is it just marketing hype?
Can you edit your answer to provide a summary of the contents of those documents and their implications for the answer to the question that was asked here? As it stands, the main content of your answer is the links, but on this site we tend not to like link-only answers very much, because links may rot or disappear.
Mar
28
answered Proof of storage scheme
Mar
28
comment Is substitution with random prefix codes secure?
@Mok-KongShen, that's of course a different question, and of course the answer to that question will probably depend on the details. This is not a discussion forum: one question per question, please (so it's important to make sure that you frame your question well so it reflects what you really want answered).
Mar
28
comment What might be assumed about a PRF if the key has been chosen?
I'm confused by "what might be assumed about..." -- you can of course assume anything you want. Do you mean, assuming only that $f$ is a PRF, what can we say about security if the key parameter is not chosen randomly? If so, the answer is: there are no guarantees whatsoever. There are bad cases where the function $f$ is no good at all, if the key is predictable or has low entropy. In TLS, the spec calls the function a PRF, but actually the protocol implicitly requires stronger assumptions than just that it's a PRF; it also needs to have some hash-like properties as well.
Mar
28
answered Is substitution with random prefix codes secure?