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comment How efficient is the error correcting code?
Maybe it would help if you explained what you are using the information for. If someone said AES-256 takes X cycles/byte and Reed-Solomon decoding takes Y cycles/byte, how would you find that helpful? And since they solve such different problem, what basis is there for selecting the two algorithms that we are quantifying?
Feb
9
comment Client-Server application how can data be encrypted so only clients can read it
There has to be some kind of authentication framework, since encrypting data is pointless unless you can verify that you're communicating with the correct person. If this is just random strangers sharing data there's no way to tell if one of them is (acting on behalf of) the server.
Feb
6
answered Client-Server application how can data be encrypted so only clients can read it
Jan
30
awarded  Yearling
Jan
30
answered Is there any existing cipher capable of scaling from a 1 bit key up to a one-time-pad?
Jan
22
comment Compact digital signature for noisy data
@fgrieu Reed-Solomon codes are non-binary, I think they can be defined over any $GF(q)$. See Wikipedia
Dec
12
comment Recovering a constant salt for MD5
"I know that the hash is of length 21" - "hash" should be "salt", no?
Dec
2
comment Using the same symmetric key in both directions?
If your attacker can't inject messages then that's not something you have to worry about. TCP provides less of a barrier than you seem to think, though.
Dec
2
comment Using the same symmetric key in both directions?
@horsehair No, the attacker wouldn't replay the TCP packets, they would replay the message in new TCP packets that go the other way.
Nov
25
comment Minimum number of independent trials needed to detect a bias
Is this just confidence intervals for a binomial distribution?
Nov
20
comment BruteForcer XOR (bfxor.exe) to attack 64-bit keys and longer
That KGB agents found themselves in this scenario once doesn't imply that it is a "common mistake", especially in the digital age. In addition, there is no reason to believe that the reused pad would be just a handful of bytes reused as many times as is necessary to encrypt an entire file. It's an interesting problem and I'm certainly not telling you to stop your pursuit, but I am absolutely not convinced that it is of any practical value.
Nov
18
comment BruteForcer XOR (bfxor.exe) to attack 64-bit keys and longer
"Now this may all be laughable in 2014 though where most cryptographers and even I use 2048 to 8192-bit (256 to 1024 Bytes) Keys for XOR encryption" - No cryptographer in 2014 is using anything like a vigenere cipher.
Nov
14
comment Random Permutation polynomial
I'm not convinced that limiting the degree of the polynomial serves a purpose, and you have the problem that low-order permutation polynomials aren't going to be very random. $x + a$ defines a permutation for every $a$, but it's just a set of permutations of size $p$.
Nov
11
comment Random Permutation polynomial
1) That's different enough that you should probably ask separately 2) I don't know 3) it doesn't really sound like a crypto question anymore, mathoverflow.net might get you better answers.
Nov
7
comment Random Permutation polynomial
Right, the $q!$ part is just counting the permutations. Proving it fully does require the fact that all functions are expressible as polynomials. This follows from the construction I gave, though there are better proofs (that escape me right now). Note that the limit on the order of the polynomial comes from $x^q = x$.
Nov
7
revised Random Permutation polynomial
added answer to question 1
Nov
7
answered Random Permutation polynomial
Oct
16
comment Are LFSRs enough for this?
hmm, I just realized b and t are not the same... I'll have to think about t < b.
Oct
16
comment Are LFSRs enough for this?
An edit is fine with me, though I don't think you should make any more. Too many edits and it's a conversation, which the platform doesn't do well.
Oct
16
revised Are LFSRs enough for this?
considered new premise