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seen Nov 24 at 17:24

Nov
24
answered What is the difference between a bijective random oracle and a random permutation?
Nov
21
awarded  Nice Question
Nov
20
comment How to prove this LFSR equation?
I suggest you edit the question to include that information, to make this question self-contained, as well as to define the notation $(f,g)$ and $[f,g]$ for polynomials and $+$ for solution spaces. Also, I suggest you edit the question to show what you've tried so far and where you got stuck.
Nov
18
comment Should we sign-then-encrypt, or encrypt-then-sign?
@louism, that's a separate question. This isn't a discussion forum -- questions should be posted separately (see the Ask Question on the upper right). But make sure to first read the help center, and do your research (try to answer the question on your own using Google, Wikipedia, search on this site, etc.) before asking.
Nov
17
comment Bellovin 96' attack on IPsec ESP protocol on encryption only option
Did you read the description in the paper carefully, one step at a time? Where did you get lost? Are you familiar with other attacks on modes of operation?
Nov
16
comment Homomorphic (encrypted) comparison to an integer
OK, much better! Now I believe that this should work. +1. Thank you for your patience with all my questions and doubts.
Nov
15
revised PAK Diffie-Hellman vs. sharing high-entropy key
rolled back to a previous revision
Nov
14
comment Has threefish successfully been attacked (practically or theoretically)?
What research have you done? Have you done a literature search? We expect you to make some effort to find out the answer on your own before asking, and to show what you've tried so far.
Nov
10
comment Perfect Forward Secrecy in MTI/A0
I encourage you to define the terminology you use (e.g., MTI/A0, LL-key), as I'm not familiar to them. Also, if you have a link to the paper(s) that introduce this scheme, I encourage you to post them. This might increase the chances that you get a good answer.
Nov
9
revised How can an encryption scheme be indistinguishable with multiple messages but vulnerable to an adaptive chosen-plaintext attack?
added 186 characters in body
Nov
9
revised How can an encryption scheme be indistinguishable with multiple messages but vulnerable to an adaptive chosen-plaintext attack?
added 186 characters in body
Nov
9
comment Why is it important to generate a pseudorandom permutation from a pseudorandom function?
What do you mean by "it is important [to do it this way]" or "it is necessary [to do it this way]"? I think you have a misconception/erroneous premise. This is one popular way to build a block cipher, but it's not the only way. It is neither necessary nor important to construct the block cipher this way. There are other ways to construct secure ciphers; see, e.g., AES/Rijndael.
Nov
9
answered How can an encryption scheme be indistinguishable with multiple messages but vulnerable to an adaptive chosen-plaintext attack?
Nov
7
comment partial-domain permutation and strong assumption
Did you read the cited paper on OAEP? I would expect that it's likely to have a definition of those terms.
Nov
7
comment What aspects of information theory are used in modern cryptography?
I suspect this is too broad to be a good fit for this site: you could probably write a whole book about it. (Also, the answer depends on what you mean by a "working cryptographer".)
Nov
7
comment Are there any bijective one-way functions not based on number-theoretic hardness assumptions?
The term you are looking for is "one-way permutation". There are many candidate constructions. Why would you insist that you are not willing to rely upon number-theoretic hardness assertions? That seems unnecessarily limiting and not well motivated.
Nov
5
awarded  Enlightened
Nov
5
awarded  Nice Answer
Nov
5
comment Is this hand cipher any more secure than the Vigenère cipher?
user54609, I asked about 7 different questions, and you answered about 4 of them. Still wondering about the other 3.... If you're not going to answer requests for clarification, how do you expect to get a good answer? Seems odd to place a bounty but not answer such questions. You should also be editing the question to include these clarifications in the question, so people don't need to read the comment thread. P.S. You might also want to notify me when responding, by including "@D.W." in your response.
Nov
5
comment How to design a secure data container?
@MaxthonChan, you can encrypt the data with something like GPG, and that'll handle both data at rest and data in motion (you can send the encrypted data over a network). Make sure to use both confidentiality and integrity/authentication.