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 Jan 26 wiki created blake2 excerpt Jan 26 suggested approved edit on blake2 tag wiki excerpt Jan 26 revised How does BLAKE2 ensure that hash(A) != hash(B) when B = A||0 and both A & B have the same number of blocks? edited tags Jan 26 answered Decrypt files with original file CTB-Locker Jan 26 awarded Yearling Jan 6 comment Are there cryptographic hash functions which do not have any collisions? @fgrieu Indeed, but that can be considered practically infinite for most intents and purposes - perfect hash functions on the other hand usually have such a small domain that they can hardly be called cryptographic. most of them, anyway. (in my experience) Jan 5 comment Is there a hash function which has no collisions? Perfect hash functions are not cryptographic hash functions as their domain is finite. Jan 5 comment Are there cryptographic hash functions which do not have any collisions? Perfect hash functions are not cryptographic hash functions as their domain is finite. Dec 26 awarded Enlightened Dec 26 awarded Nice Answer Dec 24 answered Significance of 3mod4 in squares and square roots mod n? Dec 23 awarded Cleanup Dec 15 comment How to customize a standard encryption algorithm? What do you mean by "customize"? Do you really want to modify the entrails of the algorithm, or do you just need a parameterized block cipher built on top of AES (with provably equal strength) to differentiate it from other uses of AES, akin to Skein's personalization string? Dec 12 comment Crack RSA with imaginary algorithm @AndrewPoelstra Finding multiplicative inverses is always easy, Euclid came up with a working algorithm over two millenia ago. What is hard without the factorization is finding multiplicative orders. Dec 11 comment 2048-bit RSA Decryption @fgrieu "problem solved" doesn't sound like breaking an honor code to me. Anyway, the question has been rolled back (thanks CodesInChaos). Dec 11 comment 2048-bit RSA Decryption What is the point of deleting questions? If you do that, nobody else can benefit from it later on. Please consider posting your solution as an answer for future visitors. Dec 9 answered Fermats Little Theorem, primitive root Nov 30 comment Is this problem based on a known hard problem? Well for starters the set of $a_i$ can't be linearly independent otherwise this amounts to solving an $i \times n$ system $Ab = c$ for $b$ with $A$ invertible. It can be solved in the rationals and then scaled to get an integer solution. And for linearly dependent $a_i$, I would imagine some partial solution could be obtained as well (if one exists) using the same techniques. Unless I am misreading the problem... Nov 29 comment Does SHA-1 hash have quasi commutative property? Are you going to ask the same question for SHA-2 and SHA-3 as well? crypto.stackexchange.com/questions/20497/… Nov 28 comment Issue about randomness : what if random looks “human” ? The very first thing to realize is that randomness is not a property of any particular output sequence. The sequence "1234" is neither random nor predictable, it's meaningless to refer to it as random. Rather, randomness is a property of the process used to generate them. Once you understand that, things begin to seem less paradoxal.