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 May30 comment Applying multiple hash functions to improve security? Multiple iterations of the same hash is often useful. However, Ha(Hb(Hc(Hd(message)))) is only as strong as the weakest in the chain. May30 comment Cryptographic Algorithm/Protocol needed @esskar Don't bother spending money on draconian DRM that won't actually do anything. Instead, get a lawyer to draft up an NDA for all staff that have access to your valuable assets (e.g. source code, design specs, etc) and implement strong working practices to ensure that data can't be leaked accidently. Keep an air-gap between your development network and your internet-access/email network. That way, you can take disciplinary action if someone violates procedure, or legal action if someone violates their NDA. May27 answered Brute force a ciphered message? May27 accepted Galois fields in cryptography May27 comment Galois fields in cryptography This is an amazing answer. I get it now! :) May26 comment Is it secure to use the hash of key as the IV in AES encryption? @CodeInChaos Paranoia! :) May25 comment Galois fields in cryptography I'm still lost. I understand vectors as a small set of numbers. So, a vector has a size and a set of values - essentially an array. A vector $[a,b,c,d]$ has a length of 4 and four values - $a$, $b$, $c$, and $d$. If a field is a set of vectors, I envision it as: field = array(array(a1,b1,c1,d1),array(a2,b2,c2,d2),...). Is this correct? If so, how are a1, b1, etc. computed initially, ignoring operators? Or do we just populate them with something (e.g. a key) and then do operations on them? May25 accepted Standard symbol / notation for “x knows y”, or the inverse May25 comment Standard symbol / notation for “x knows y”, or the inverse @CodeInChaos I was just using it as an example. If I were really writing that in a document, I'd put something like "where $f(x)$ runs in polynomial time or better". May25 comment Standard symbol / notation for “x knows y”, or the inverse So you're saying there's no such notation? May25 asked Standard symbol / notation for “x knows y”, or the inverse May25 accepted Is every output of a hash function possible? May25 revised Galois fields in cryptography example May25 revised Galois fields in cryptography update May25 comment Galois fields in cryptography <<*snip*>> - I've put this comment as an update to the question. May24 asked Galois fields in cryptography May24 comment Memory-hard operations in work-factor hash functions @CodeInChaos I am using scrypt, in my production code. This is just something I'm playing with out of interest, to see how I might go about creating a memory-hard hash function. May24 comment After implementing a novel encryption algorithm, how would one go about analyzing its security or get help from others in doing so? Can't +1 poncho's comment enough. Learn to break ciphers! I aso recomment Stanford's free crypto course. May24 comment After implementing a novel encryption algorithm, how would one go about analyzing its security or get help from others in doing so? I think you misunderstood. I'm saying that you shouldn't use your own schemes in practice, for any form of security mechanism in a production environment. You can devise your own schemes and get critique to learn about crypto, but please don't ever use your own cipher to secure sensitive information. Real ciphers have been developed by serious crypto gurus and vetted by hundreds of other serious crypto gurus, over a period of many years. Not a single one of them would use their own cipher without years of peer review and revision. May24 asked Memory-hard operations in work-factor hash functions