147 reputation
9
bio website
location
age
visits member for 1 year, 2 months
seen 11 hours ago

Oct
15
comment Comparing Files: Is it better to use multiple hash algorithms or just one?
@Gutblender Indeed, MD5 does many computations on whole file.
Oct
15
revised Adding tweak to a block cipher
Threefish seems to be distractive
Oct
15
comment Comparing Files: Is it better to use multiple hash algorithms or just one?
Byte-for-byte comparison is faster than MD5 or CRC, unless you don't want to upload whole file and you compute hash on client's computer. But if files are small why bother? Is this cryptography related?
Oct
14
comment Adding tweak to a block cipher
@Thomas I'm not saying that Threefish key schedule is being vulnerable to attacks. But every round key bit does not depend on all key bits, it is reversible and it is repeating (even if permuted). That is weak key schedule, which doesn't mean block cipher is weak.
Oct
14
comment Adding tweak to a block cipher
@owlstead added citation
Oct
14
revised Adding tweak to a block cipher
citation added
Oct
13
asked Adding tweak to a block cipher
Oct
13
accepted SpongeWrap without padding and frame bit
Oct
13
awarded  Curious
Oct
10
asked SpongeWrap without padding and frame bit
Jun
2
comment Parallel hash construction
@user1028028: PMAC without key is completely insecure. Fix it, how?
Jun
1
comment Parallel hash construction
@user1028028: I'm asking about hash, not MAC.
May
31
accepted Parallel hash construction
May
31
revised Parallel hash construction
equations fixed
May
31
asked Parallel hash construction
May
19
awarded  Commentator
May
19
comment Pseudo-Hadamard transform, most significant bit
@poncho: Sorry, my mistake. It doesn't.
May
17
comment Pseudo-Hadamard transform, most significant bit
$b = b' \oplus a' \, \pmod{2^n}$ $a = (a' \oplus b') - b' \, \pmod{2^n}$
May
17
comment Pseudo-Hadamard transform, most significant bit
I don't think this is a problem. However you could improve it by doing: $a' = a + b \, \pmod{2^n}$ $b' = (a + b) ⊕ b\, \pmod{2^n}$ This would also add some non-linearity.
May
15
comment Is TEA considered secure?
Attack with time complexity of $2^{121.5}$ is on 21 of recommended 64 rounds.