11,606 reputation
11049
bio website vyznev.net
location Helsinki, Finland
age
visits member for 2 years, 11 months
seen 6 hours ago

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 started programming (in AmigaBASIC) when I was 10 years old. Nowadays, I'm most comfortable using Perl, C and JavaScript. I know Java and PHP too, but I can't really say I like them. I also know some Python, but not as much as I'd like.


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.


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:


Jul
23
awarded  Revival
Jul
23
answered Reordering non-block-aligned parts with DES in ECB mode
Jul
20
answered Spoofing protocol nonce
Jul
20
revised Spoofing protocol nonce
subscripts
Jul
20
revised Spoofing protocol nonce
subscripts
Jul
18
comment Is TripleDES 168bit vulnerable to Differential Cryptanalysis?
@owlstead: Agreed. Not only is it full of both factual and grammatical errors, but most of the text, or at least the more fluent parts of it, appears to be plagiarized. If this were an undergrad course assignment, I'd give it an F; since the authors appear to be grad students, and since it appears to have been published in something pretending to be a scientific journal...
Jul
14
awarded  Nice Answer
Jul
1
revised Exactly two of the four roots must be greater than N/2
add the symmetry argument to the answer; feel free to improve
Jun
28
revised Condensed ElGamal + AES
make Wikipedia URL non-mobile (and protocol-relative)
Jun
9
awarded  Nice Answer
Jun
5
reviewed Close AES/CBC fixed Initial vector use-case
Jun
5
reviewed Leave Open Use of Different keys with PCBC
Jun
4
comment Why is TLS SRP verifier based on user name?
@simbo1905: The compromised server wants to know if Alice and Bob have the same password. So, when Alice tries to log in, the server looks up Bob's authentication data $(s_{\rm Bob}, v_{\rm Bob})$ and sends Alice $s=s_{\rm Bob}$ and (in SRP-6) $B=3v_{\rm Bob}+g^b$, gets back $M_1$ and verifies that it equals $H(A,B,S)$, $S=(Av_{\rm Bob}^u)^b$. If it does, Alice has just successfully authenticated herself as Bob, which (with overwhelming likelihood) means they must have the same password $P$ and identifier $I$. Assigning each user a separate $I$ (typically, their username) plugs this hole.
Jun
1
revised Correct way to read a given permutation cipher?
needs more t
Jun
1
answered Correct way to read a given permutation cipher?
Jun
1
reviewed Leave Open How Does Progressive Hashing Work?
Jun
1
reviewed Leave Open Why would splitting a password output be better than separate HMACs for encryption/authentication key derivation?
Jun
1
revised Choice of MAC and handling it correctly
being privacy-preserving is not enough
May
31
comment Encryption of log files
Using a stream cipher (or a block cipher in CTR mode) would be tempting, but would be vulnerable to an attack where the attacker deliberately truncates the log file before letting your program append to it, in order to obtain multiple logs encrypted with the same keystream. Still better than just XOR with a static key, though.
May
31
answered Choice of MAC and handling it correctly