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I like crypto. Need I say more?


36m
revised Questions on FHE over the Integers
added tex formatting
2d
comment Public key Issue - same key pair as existing one?
Related question or possibly even a duplicate.
2d
comment Public key Issue - same key pair as existing one?
It is very unlikely if everything is done properly (i.e., a good random number generator is used). Unfortunately, it has happened in practice. See the Debian OpenSSL RNG bug also this paper which details other issues found in practice.
Jul
25
comment Key Derivation from random salted seed, HMAC and HMAC based KDF
Note that you have another question on here with the exact same title.
Jul
25
comment Key Derivation from random salted seed, HMAC and HMAC based KDF
If you use the proper OS provided random number generators, then yes, they are good enough for encryption.
Jul
25
comment Key Derivation from random salted seed, HMAC and HMAC based KDF
To add to what otus says, most operating systems have built in random number generators. Most mobile device platforms (iOS and Android) have good random number generators built in. Why not just generate a 128-bit (or 192 or 256) random value and use that directly?
Jul
24
revised Vigenère cipher: Security when key length and plaintext length are the same
edited tags
Jul
22
revised How can I solve this modular equation?
deleted 21 characters in body
Jul
22
comment How can I solve this modular equation?
Compute the multiplicative inverse of 5 mod 13 (using extended euclidean algorithm). Then multiply 2 by that value. Viola, you have x.
Jul
22
comment RSA with modulus n=p²q
@Thor, I don't think CGFoX is planning on making the primes smaller to achieve the same bit size. Especially since the question specifies that using $p^2q$ would allow operations on a bigger $\mathbb{Z}_n$. That said, if the only benefit is a larger group, I would just pick larger primes to get the larger group personally (as you suggest).
Jul
22
revised MAC using a modified CBC mode of operation
edited body
Jul
22
revised RSA with composite numbers
added 6 characters in body
Jul
22
revised MAC using a modified CBC mode of operation
deleted 10 characters in body; edited tags
Jul
22
comment Lowest number challenge scheme
@fkraiem remember though, you would have to always run the coin-flip (whether there was a tie or not), otherwise you leak whether or not there was a tie. My point is, things can get complicated.
Jul
18
reviewed Approve suggested edit on Polynomial representation of the affine part of the AES S-box
Jul
18
comment Polynomial representation of the affine part of the AES S-box
Could you explain what l0-l8 are? I'm too lazy to read the paper right now.
Jul
18
comment Storing encryption key
Is this a stand alone app, or a client server app?
Jul
17
revised Given $g$, $b$, $g^{ab}$, is finding $g^a$ a hard problem?
rolled back to a previous revision
Jul
17
revised Given $g$, $b$, $g^{ab}$, is finding $g^a$ a hard problem?
Tried to make the computations more explicit.
Jul
17
comment Are there any reasons for using SSL over IPSec?
@CodesInChaos, you are right. I am pinging the mods.