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Katie in raining icebergs save unknown ricocheting Finns, m i r a i .bla koh dotvu, bloo gah soo shup.


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.
Nov
11
comment Are there public $p$ and $q$ numbers for use in DSA?
Where? I can't find any.
Nov
11
asked Are there public $p$ and $q$ numbers for use in DSA?
Nov
6
awarded  Benefactor
Nov
6
accepted Is this hand cipher any more secure than the Vigenère cipher?
Nov
1
comment Is this hand cipher any more secure than the Vigenère cipher?
The key is a repeated word, like in Vigenère.
Oct
30
comment Is this hand cipher any more secure than the Vigenère cipher?
Could you explain a bit how repetition would be bad? Unlike the Vigenère, crib-dragging and usual attacks on Vigenère don't seem to work. With multiple rounds, I am under the (false) impression that the multiple linear additions combined with the fixed permutation give a random-to-the-human-eye, nonperiodic, keystream.
Oct
30
comment Is this hand cipher any more secure than the Vigenère cipher?
That is in fact what I had in mind when I mentioned "very slow" hand ciphers...
Oct
30
awarded  Promoter
Oct
30
comment OFB or CTR mode without an IV
Theoretically the maximum size is 65536 bytes, but usually libraries send records with size 4096 bytes and less.
Oct
28
accepted How does SSL secure the initial handshake?
Oct
27
comment How does SSL secure the initial handshake?
So in the real world, as long as the servers are configured not to support weak ciphers, the Finished messages don't really matter?
Oct
27
comment How does SSL secure the initial handshake?
What if the attacker forces the client and server to negotiate the NULL cipher?
Oct
27
comment OFB or CTR mode without an IV
I'm assuming that the question was more like is it possible to use CTR or OFB mode securely without transmitting IV. I.e. for instance, start at all zeroes IV/counter and increment the counter for each message.. You seem to be the only person to have understood my question :)
Oct
27
comment How does SSL secure the initial handshake?
Yes, I mean TLS. SSL 3.0 isn't severely deprecated, though. I think it is still widely used. SSL 2.0 is the badly insecure one.