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May
17
awarded  Good Answer
May
17
reviewed Approve suggested edit on universal-composability tag wiki excerpt
May
17
reviewed Approve suggested edit on tea tag wiki excerpt
May
17
reviewed Approve suggested edit on sha-3-competition tag wiki excerpt
May
17
reviewed Approve suggested edit on software-obfuscation tag wiki
May
17
reviewed Approve suggested edit on software-obfuscation tag wiki excerpt
May
17
reviewed Approve suggested edit on sha-3-competition tag wiki
May
17
reviewed No Action Needed Pseudo-Hadamard transform, most significant bit
May
16
comment Is concatenated data hashed with scrypt vulunarable to a length extension attack?
@AdamSmith: actually, with MD5, they couldn't guess the value of MD5("foobar1") given MD5("foobar"). Now, given MD5("foobar"), there is a specific extension that looks something like MD5("foobar\x80\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\‌​0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\6\0\0\0\0\0\0\0More stuff here") (where the "More stuff here" part can be chosen by the attacker arbitrarily) which can be computed as a function of MD5("foobar") -- it counts as a "length extension" attack, however it's not likely to be the sort of thing one would pick as a password normally.
May
16
comment Is concatenated data hashed with scrypt vulunarable to a length extension attack?
@AdamSmith: if you trust scrypt, then that iterated HMAC is unnecessary; all you need is a collision-free mapping between the parts to the password you actually give scrypt (and concatenation can obviously be collision-free); scrypt's of two different passwords are independent, even given a known relationship between the two passwords. Now, if you don't trust scrypt, you can obviously do the iterated HMAC's as you said -- however, if you didn't trust scrypt, why are you using it?
May
16
answered Is concatenated data hashed with scrypt vulunarable to a length extension attack?
May
16
comment RSA private exponent primality
@Thomas: indeed, you expressed it better than I did
May
15
revised What is a generator?
Extended explination
May
15
answered What is a generator?
May
15
reviewed Delete How much would it cost in U.S. dollars to brute force a 256 bit key in a year?
May
15
reviewed Leave Open Computing youngest person among 3 while keeping ages private
May
15
answered RSA private exponent primality
May
15
reviewed No Action Needed RSA private exponent primality
May
14
revised Breaking RSA when some bits of one prime are known
edited tags
May
9
awarded  Disciplined