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Oct
15
wiki created random-number-generator excerpt
Oct
15
comment Does AES have any fixed-points?
@Fixee: You are right. I added some clarification using the information from the comments.
Oct
15
revised Does AES have any fixed-points?
add disclaimer from comments
Oct
15
comment An Elliptic curve cryptography implementation which can be terminated
Do I understand right, this means that factoring our composed modulus is quite easier than solving discrete logarithms in the curves over the resulting smaller rings (instead of the other way around), and ByteCoin's proposed method will not work?
Oct
15
comment Does AES have any fixed-points?
@ByteCoin: No, I have no ideas. Just the space of fixed-point-free permutations is large enough that we can choose only from those without introducing some weakness by this alone. I hope we get some answers from people which know more about AES (did some cryptanalysis or read the corresponding papers). My argument here is a generic one which is valid (or not) for any block cipher of this block and key size, nothing AES-specific. (I'll edit my answer later after I've got some sleep.)
Oct
15
comment Does AES have any fixed-points?
Good point. I don't know an answer here (and I'm not sure there is one). Actually I would not be too surprised if AES is made to have fewer fixed points than expected, or none at all.
Oct
15
answered Does AES have any fixed-points?
Oct
15
comment How can I store confident data with OpenID?
Do you mean "securely" = "only the OpenID owner has any chance to decrypt it"?
Oct
15
comment An Elliptic curve cryptography implementation which can be terminated
The ring $\mathbb{Z}/n\mathbb{Z}$ is not a field, if $n$ is composite. This might even having elliptic curve arithmetic complicated, not to speak of security at all.
Oct
15
comment How do I apply differential cryptanalysis to a block cipher?
Are the books these? Cryptography Theory and Practice (Douglas Stinson), Differential Cryptanalysis of the Data Encryption Standard (Eli Biham + Adi Shamir). (If so, simply edit the links into your answer.)
Oct
14
revised What are the practical differences between 256-bit, 192-bit, and 128-bit AES encryption?
add paragraph about quantum computer (from comments by Jack Lloyd and Thomas Pornin)
Oct
14
revised How can a random salt for a hash function work in practice?
better title, some punctuation
Oct
14
revised How to provide secure “vanity” bitcoin address service?
some more arguments about number of iterations, partly from nealmcb's comment.
Oct
14
revised How to provide secure “vanity” bitcoin address service?
adding optimization from comment by Nakedible
Oct
14
revised How to provide secure “vanity” bitcoin address service?
formatting
Oct
14
revised How were the DES S-box values determined?
add information from comments
Oct
14
comment AES in ECB mode weakness
The main problem with ECB mode is that identical plaintext blocks (encrypted with the same key) always result in identical ciphertext blocks (and different ones result in different ones). Could this be a problem in your case?
Oct
13
revised Key Length & Hashing
adding information from the comments, adding links
Oct
13
revised Strength of multiple hash iterations?
formatting fixes
Oct
13
revised Key Length & Hashing
edited tags