Ricky Demer
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 May 24 comment RSA with probable primes "crept happens" $\: \mapsto \:$ "crept in happens" $\;\;\;\;$ May 24 comment RSA with probable primes residuals $\mapsto$ residual $\;$ May 24 comment Executing encrypted code? May 24 comment RSA with probable primes May 23 revised Does the One Time Pad rely on confusion or diffusion? fixed title's spelling May 23 revised How to prove that someone encrypted a specific (large) chunk of data fixed title's grammar May 23 comment Huffman encoding of hashes How about a base-256 encoding? $\:$ (aka, not encoded at all) $\;\;\;\;$ May 23 comment Huffman encoding of hashes They can be encoded with just 20 characters. $\;$ May 23 comment Huffman encoding of hashes No, but getting farther away from that requires more output for a given security level. $\hspace{1.41 in}$ May 23 revised Factorization of a number obtained by a modular multiplication operation can reveal factors of the used operands? fixed spelling and grammar May 22 comment Authenticated EC key exchange without a signing/signature scheme? @StevePeltz : $\:$ Yes. $\;\;\;\;$ May 22 revised Authenticated EC key exchange without a signing/signature scheme? changed PAKE link May 22 comment Hard-core predicates: should the adversary be given $1^n$? $B$ can just run $A$ with $n$ ranging from $0$ to $\:2\hspace{-0.03 in}\cdot \hspace{-0.03 in}\operatorname{length}(\hspace{.03 in}y)\:$,$\:$ since injective functions have negligible probability of shrinking random inputs by large amounts. $\;\;\;\;$ May 22 comment Hash length extension attack - SHA256 to 512 - impossible, correct? Of course, it would probably be better is the user can see a commitment to the secret instead of the SHA256 hash of the secret, and if the user-key is then HMACed with the secret instead of them being hashed with SHA512. $\;$ May 21 comment Would this method deliver a perfectly non-malleable encryption for at least two blocks? "The second block" of the ciphertext "includes the propagation ... intermediate block". $\:$ "The second block" of the plaintext is not affected by the IV. $\;\;\;\;$ May 21 comment Would this method deliver a perfectly non-malleable encryption for at least two blocks? The version you have at the moment (you might still be editing) is still malleable because changing $\hspace{.42 in}$ the IV would change block1 of the decryption result but not block2 of the decryption result. $\hspace{.92 in}$ May 21 comment Would this method deliver a perfectly non-malleable encryption for at least two blocks? Now that I'm actually looking at your decryption procedure, I see that your scheme is very malleable, $\hspace{.13 in}$ since xoring the IV with any string will xor the result of decryption with the same string. $\hspace{1.19 in}$ May 21 comment Would this method deliver a perfectly non-malleable encryption for at least two blocks? You should also note that if 128 is large, then there is a simple&standard way to do the no-ciphertext-expansion version of what you're trying for, although it's slightly less efficient than your third version. $\;$ May 21 comment Would this method deliver a perfectly non-malleable encryption for at least two blocks? It looks like your third version requires 4 encryptions per block, 2 with each key. $\;$ May 21 comment prepaid meters that rely on a disconnected system Why doesn't asymmetric "fit the architecture of one server sending to many clients"? $\hspace{1.29 in}$