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I starts with all relevant references I found, then tentatively answers the question. Feel free to improve this community wiki. It was originally asked the effort to break PKZIP 2 encryption, described in section 6.1 of the .ZIP File Format Specification (with some refinements in the derived Info-ZIP appnote), assuming a high-entropy password (that is, ...


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The problem can be simplified to the following problem, since the standard argument doesn't really take into account that you can't generate all the polynomials of the given maximum degree : Assume that we have sampled a random point $\vec{x}\in \mathbb{F}_p^n$. We let an adversary adaptively choose polynomials of degree at most $d$ and after each choice ...


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The -bf-ecb cipher is expanding the key to 128 bits by zero extending it. The output from -p is the telltale here: $ openssl enc -bf-ecb -e -in plaintext.txt -out ciphertext.txt -nosalt -K FFFFFFFFFFFFFFFF -p key=FFFFFFFFFFFFFFFF0000000000000000 Blowfish is defined for 32-448 bit keys, and it appears the OpenSSL implementation chose 128 bits as the size ...


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It's much easier to add a cost factor to the key derivation from the password than to add a lot of data to an encrypted container. See the PBKDF's PBKDF2, bcrypt and scrypt for more information, or see this Q/A for GPG. In general, an iteration to derive the key is of course much more efficient than adding overhead at the start of the file. If a key with an ...


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I'm not aware of any implementations, but I'm also not aware of any patents on this algorithm. Also, one can generically make such schemes tweakable via tFPenc(key,tweak,plaintext) = FPenc(PRF(key,tweak),plaintext) and tFPdec(key,tweak,ciphertext) = FPdec(PRF(key,tweak),ciphertext) .


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My implementation of Serpent is bit-sliced, so there is no initial permutation involved in generation of my round subkeys. It is also NESSIE byte ordered, which means that vectors will not match the AES submission package. I assume that IP will reorder the bits appropriately if you are using a non bit-sliced version. I just rewrote most of my implementation ...


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The notation you are seeing is for symmetric crypto. Garbled circuits typically use symmetric crypto since it can and symmetric crypto is fast. You may be able to do garbled circuits with asymmetric crypto, but it is definitely non-standard and may have subtle issues.



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