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Dec
19
comment Is a Mersenne-twister cryptographically secure if I truncate the output?
Wow. There's a pretty impressive amount of misconception shown here. All I can say is: You are not qualified to write a casino game. Don't do it. There is specific technical knowledge required to do this right, and you do not have it. Try to find someone more qualified to do this aspect of design, because your instincts are leading you astray, your reasoning is wrong, your conclusion is wrong (and worse, you seem convinced that you are right).
Dec
17
answered Attacks against El Gamal private key
Dec
17
revised Help with linear cryptanalysis
Add Matsui paper.
Dec
17
comment Help with linear cryptanalysis
@Antimony - yup, that's certainly possible! The only thing I couldn't tell was: what is the best characteristic you've gotten? How many rounds, and with what bias (or what probability)? It's possible that if you asked a new question giving that specific characteristic and asking if anyone can do better, maybe someone would be inspired to try to find a better one and see if they can beat what you got. Anyway, great question -- sorry I wasn't able to give a more specific answer focused on this particular cipher.
Dec
16
revised Help with linear cryptanalysis
References.
Dec
16
revised Help with linear cryptanalysis
References.
Dec
16
revised Help with linear cryptanalysis
added 2357 characters in body
Dec
16
answered Help with linear cryptanalysis
Dec
16
comment Combining two hashing functions
possible duplicate of Guarding against cryptanalytic breakthroughs: combining multiple hash functions
Dec
16
comment Combining two hashing functions
Are you using cryptographic hash functions? If not, this is off-topic for Cryptography.SE.
Dec
15
comment Randomized stream cipher using multivariant quadratic equations
@Antimony, yeah, $n^2/2$ should suffice. I wasn't trying to optimize the constant factors (just laziness). Thank you.
Dec
12
awarded  Nice Answer
Dec
11
revised Block Cipher Mode Amicable to Fast Key Change/Rotation Like XOR?
added 519 characters in body
Dec
11
comment Block Cipher Mode Amicable to Fast Key Change/Rotation Like XOR?
@DrLecter, thanks for the elaboration -- good point. If the document changes, you can consider the new version a new document (with its own key). I've edited my answer correspondingly. Thank you!
Dec
11
comment Do test vectors ensure a cipher is free of backdoors?
@CodesInChaos, yup, absolutely. But, I don't think mikeazo ever claimed that's the best or only way to insert a backdoor. To answer the question in the negative, it suffices to show one example of a backdoor -- it doesn't have to be the best possible backdoor.
Dec
11
revised Block Cipher Mode Amicable to Fast Key Change/Rotation Like XOR?
added 10 characters in body
Dec
11
comment Block Cipher Mode Amicable to Fast Key Change/Rotation Like XOR?
@noloader, It's not a problem. Think about it this way: What does knowledge of the document key for document $D$ let you do? It lets you decrypt document $D$. But if you give that key to everyone who should be able to read $D$, then you're not allowing them to do anything they shouldn't be able to do. It's not the same "everyone shares the wireless gateway password" because my answer shows how to communicate the document key to a person. There is no revocation: once you've allowed someone to download document $D$, you're done, there's no going back: they've got a copy of $D$, period.
Dec
11
answered Block Cipher Mode Amicable to Fast Key Change/Rotation Like XOR?
Dec
11
revised RC2, RC4, RC5 key length
added 278 characters in body
Dec
11
answered Can one use a Cryptographic Accumulator to efficiently store Lamport public keys without the need of a Merkle Tree?