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seen Jul 20 at 12:17

Aug
23
revised What signature schemes allow recovering the public key from a signature?
removed non-obvious reference to an entirely different problem
Aug
23
comment What signature schemes allow recovering the public key from a signature?
With "recovering the private key", I was referring to the troubles with ECDSA and reused nonces that somewhat famously resulted in Sony's PS3 master keys being published and about 55 Bitcoins being stolen. Of course, when using a proper random nonce, this is not possible. One might say that it's only the implementor's fault, but proper randomness can sometimes be hard to acquire... I've now removed that sentence; vaguely referencing ECDSA's security model probably doesn't add anything to the question.
Aug
23
revised Can one have an authentic, but repudiable, message without a previously shared secret?
Encrypting the signature might be safer, depending on the asymmetric algorithm (see comments)
Aug
23
comment Can one have an authentic, but repudiable, message without a previously shared secret?
@poncho: That's correct, Alice can't create exactly the same message. However, since by the protocol, K is randomly chosen for every message, the only information that can't be repudiated by bob is "at some point, Bob authenticated a message using K". Depending on the application, that might be acceptable.
Aug
23
awarded  Teacher
Aug
23
revised Can one have an authentic, but repudiable, message without a previously shared secret?
forgot the mac tag in the message
Aug
23
asked What signature schemes allow recovering the public key from a signature?
Aug
23
answered Can one have an authentic, but repudiable, message without a previously shared secret?
Jul
28
awarded  Nice Question
Jul
20
awarded  Yearling
Jul
19
accepted Can CBC-encrypted files be modified in-place?
Jul
18
asked Can CBC-encrypted files be modified in-place?
Jun
7
awarded  Popular Question
May
25
accepted Are cryptographic hash functions perfect hash functions?
Apr
23
revised Are cryptographic hash functions perfect hash functions?
deleted 26 characters in body
Apr
23
asked Are cryptographic hash functions perfect hash functions?
Feb
17
comment Why does WPA-PSK not use Diffie-Hellman key exchange?
Michael already suggested a method that provides stronger security: A Diffie-Hellman exchange. This would require an attacker to actively perform a man-in-the-middle-attack, as opposed to starting Wireshark and entering the PSK. I'm also wondering why they didn't implement it like that.
Feb
12
comment Is semantic security important in a hybrid cryptosystem?
Your're right, that was a typo - I meant random plaintext as input to the asymmetric cipher. I've changed the question accordingly. Thanks!
Feb
12
revised Is semantic security important in a hybrid cryptosystem?
added 4 characters in body
Feb
11
accepted Is RC4 a problem for password-based authentication?