13,720 reputation
11458
bio website vyznev.net
location Helsinki, Finland
age
visits member for 3 years, 7 months
seen Mar 24 at 1:45

I'm not really a cryptographer, I just play one on the Internet. ;-)

I'm a PhD student in biomathematics, working on stochastic individual-based models of evolution in spatially structured populations. My other interests include cryptography, programming games and puzzles, photography and graphic design.


I'm the main author and maintainer of the Stack Overflow Unofficial Patch (SOUP), a user script for browsers with GreaseMonkey-compatible user script support (Firefox, Chrome, Opera, possibly Safari) that fixes or works around a number of outstanding issues with the Stack Exchange user interface.

I tend to answer a lot more questions than I ask. Some answers I'm rather proud of:

CC-Zero Please consider any (original) code I post to Stack Overflow and other Stack Exchange sites to be released under CC-Zero unless stated otherwise. You may do whatever you want with it and don't have to credit me in any way, although of course that would be nice.


Mar
11
answered Inconsistent terminology for ciphers and algorithms
Mar
11
reviewed Close How to compute accumulated values in bilinear map accumulators
Mar
11
reviewed Reviewed What is the probability of finding 4 equal bytes?
Mar
11
answered Is creating a own protocol safe or should TLS always be used?
Mar
11
comment Composing two one-way functions such that the result is not a one-way function
Ps. If you really must have two distinct one-way functions, you could always, say, use $1^{n/2}$ instead of $0^{n/2}$ for one of them.
Mar
11
revised Composing two one-way functions such that the result is not a one-way function
copyedit
Mar
11
comment Is $f(x)\oplus x$ a one-way function?
Just FYI, I borrowed your construction for a (community wiki) answer to a related question.
Mar
11
answered Composing two one-way functions such that the result is not a one-way function
Mar
11
revised Is $f(x)\oplus x$ a one-way function?
move period inside display math, add some paragraph breaks
Mar
11
awarded  block-cipher
Mar
10
reviewed Close how to integrate 2-3 algorithms to encrypt large data fastly and securely insted using AES?
Mar
10
reviewed Leave Open Standard serialization format for libsodium-based messages
Mar
10
reviewed Reviewed Encryption scheme that allows compare ciphertexts based on the clear text
Mar
10
comment Encryption scheme that allows compare ciphertexts based on the clear text
I've voted to close this as a duplicate (since the literal answer to your question is basically "this is called order-preserving encryption"), but +1 for a well-asked question.
Mar
10
reviewed Reviewed Possible to determine the encryption key that was used by knowing the input and output of the encryption mechanism?
Mar
10
comment Known plaintext, unknown 128 bit block cipher
Ps. Related, possibly duplicate: crypto.stackexchange.com/questions/997/…
Mar
10
reviewed Reviewed PRNG generation improved by shuffling and combinations
Mar
10
reviewed Reviewed Key length requirement in a simple XOR implementation
Mar
10
comment Key length requirement in a simple XOR implementation
Yes, it should work, because of the % klen part. (Exercise: what does that part actually do?) You could've also simply tried it yourself on some test data. (In any case, I'm voting to close this question as off topic, since it's really more about basic programming rather than cryptography. It would be a better fit for Stack Overflow.)
Mar
10
comment Known plaintext, unknown 128 bit block cipher
Alas, the one thing the paper does not seem to include is any kind of demonstration that their method actually works. In fact, for modern block ciphers with the same block size, I can fairly confidently assert that it doesn't -- if it did, the authors would be famous. (They do suggest that their program may also use side channel information, so it's somewhat plausible that it could e.g. be able to distinguish DES from Blowfish based on the time needed to encrypt a message; but that'll only work if such timing information is actually available.)