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Kids in rectangles irritating sick urchins rattling foxes, directory.kirisurf.org lol


Jul
2
awarded  Curious
Jun
3
awarded  Nice Question
May
30
awarded  Popular Question
May
29
comment Why is plain-hash-then-encrypt not a secure MAC?
@supercat Do you not mean CFB?
May
28
comment Why is plain-hash-then-encrypt not a secure MAC?
The first attack is the type of horribly devastating attack I was expecting! Thanks!
May
28
accepted Why is plain-hash-then-encrypt not a secure MAC?
May
28
comment Is TEA considered secure?
Oh I didn't test it. It just "felt" fast by looking at the simple code, compared to the huge spaghetti mess of lookup tables and advanced things like unusual field operations of other block ciphers like AES.
May
28
awarded  Yearling
May
28
comment Why is plain-hash-then-encrypt not a secure MAC?
But I'm talking about MAC-THEN-encrypt. So unless the encryption is forgeable, the MAC should be unforgeable?
May
28
asked Why is plain-hash-then-encrypt not a secure MAC?
May
17
accepted Is TEA considered secure?
May
17
comment Is TEA considered secure?
Wow that seems impressive. Why isn't TEA more widely used then? Without lookup tables etc, things like cache timing attacks are impossible, and it's trivial to implement and super fast.
May
15
asked Is TEA considered secure?
May
15
asked Is it possible to construct a secure block cipher of size $2n$ given a secure block cipher of size $n$?
Apr
12
comment Why are collision attacks important when talking about MAC schemes?
64-bit security is kinda ridiculous nowadays though. Why aren't we seeing brute-force forgery attacks on SSH, which uses HMAC-MD5, for example? Does this imply all those AES-256-GCM things are totally pointless since they could after all be using a 64-bit key?
Apr
12
comment Why are collision attacks important when talking about MAC schemes?
Does this attack work for HMAC? I seem to recall that HMAC is secure even when the underlying hashing function is vulnerable to collision attacks much faster than birthday (i.e. MD5).
Apr
12
asked Why are collision attacks important when talking about MAC schemes?
Mar
5
comment What key exchange protocols give Forward-Secrecy resisting future progress?
DHE in TLS does provide forward secrecy if properly used (no session cache etc).
Mar
4
asked Why don't we use H(m||k) as a MAC?
Nov
12
comment Is this hand cipher any more secure than the Vigenère cipher?
Okay. "Is the key a sequence of numbers that are uniformly and independently distributed (each number is uniform of all others)?" Ideally yes, but in fact the key is just a repeated word in practice to speed up memorization. Key length: variable. We use the same key in each round.