Reputation
18,548
Top tag
Next privilege 20,000 Rep.
Access 'trusted user' tools
Badges
1 28 75
Impact
~442k people reached

Feb
3
revised CPA security of a stateless and deterministic encryption system
grammar, title capitalization
Feb
3
comment CPA security of a stateless and deterministic encryption system
Essentially the same argument also works for symmetric ciphers, since the definition of IND-CPA security assumes that the attacker has access to an encryption oracle.
Feb
2
revised Decrypt a message which is encrypted using XOR?
this has nothing to do with block ciphers
Jan
14
comment Specification of the Megamos crypto algorithm
Just for posterity, let me note that the protocol description that you quote above, via the cybergibbons website, appears to be originally quoted (without attribution, alas) from my answer to this question. (The cybergibbons version also has what appears to be a minor editing mistake in the second-to-last step, where it reads ${\rm T \to C}: r,G$ instead of ${\rm T \to C}: G'$, but you seem to have fixed that.)
Jan
6
comment Encryption for a short packet size
@BaruchEven: Yes, counter mode is safe even with predictable IVs, as long as they're never repeated. Generally, only CBC mode (and certain variants of CFB) requires unpredictable IVs.
Jan
6
answered Encryption for a short packet size
Jan
6
awarded  Talkative
Jan
5
comment Why is the private key generated first in public key crypto?
@yyyyyyy: In fact, many RSA implementations do store $p$ and $q$ as part of the private key, since doing so allows using the Chinese remainder theorem to speed up the algorithm.
Jan
3
revised Why hash the message before signing it with RSA?
added 133 characters in body; edited title
Jan
3
reviewed Close RSA - Why should we sign hash rather than raw content?
Jan
3
comment Why are there no MACs inspired by block cipher modes other than CBC and CFB?
Please clarify your question, especially the statement quoted by Ricky. None of the traditional cipher modes (ECB, CBC, CFB, OFB and CTR) include a MAC, nor can they be (directly) used as one. There are MAC constructions that do bear some resemblance to these modes, such as CBC-MAC and its modern replacement CMAC, but those are separate constructions (although CBC and CBC-MAC do work very similarly). (Also, MAC usually stands for message authentication code; if you really mean mutual, please clarify that too.)
Dec
31
answered PRNG determinism (and java.security.SecureRandom)
Dec
30
revised Preventing Quantum Attacks on Cryptography
edited tags
Dec
30
revised Is the DES F-function injective for a given subkey?
copyedit (actually turned into a pretty complete rewrite)
Dec
30
reviewed Reviewed Is the DES F-function injective for a given subkey?
Dec
30
comment Is the DES F-function injective for a given subkey?
We just had a very similar (but apparently not duplicate) question less than 24 hours earlier. Just out of idle curiosity, are these coming from some online course or something, or is it just a remarkable coincidence?
Dec
30
reviewed Reviewed Attribute-based broadcast encryption with respect to ABE
Dec
30
revised DES generating the same ciphertext for different plaintexts and identical key
edited tags
Dec
29
reviewed No Action Needed How are random numbers for RSA generated?
Dec
29
reviewed Reviewed Do I have to transfer the private key to digitally sign a remote document?