11,634 reputation
11049
bio website vyznev.net
location Helsinki, Finland
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visits member for 2 years, 11 months
seen 3 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:


Sep
3
comment Using one-way hash functions as the encryption method
For each word, I suggested HMACing the previous 16 bytes (i.e. 512 bits) of the ciphertext (i.e. the part of the ciphertext encoding the previous word). You could HMAC more of the preceding ciphertext, but there's no real advantage to it. As for the hash and the key length, hiding the choice of the hash only adds at most a few bits of strength. That hardly makes up for the fact that it makes the security of your scheme harder to study. And you can use a longer key if you want, but 128 bits is enough to thwart any plausible brute force attacks using computers based on known physics.
Sep
3
revised Using one-way hash functions as the encryption method
added 243 characters in body
Sep
3
answered Using one-way hash functions as the encryption method
Sep
3
comment Using one-way hash functions as the encryption method
@jj57: Having an Enigma machine just tells you how the scheme works, not what key was used to encrypt a given message. A modern, secure encryption scheme would not have been affected in any way by an attacker obtaining an encryption device, or even a detailed schematic of one. See Kerckhoffs' principle for details.
Sep
3
revised Self-expiring symmetric keys, or: cryptography in absence of secure deletion
edited tags
Sep
3
revised Any problems with this secure time synchronization scheme?
edited tags
Sep
3
revised What is the progress on the MIT LCS35 Time Capsule Crypto-Puzzle?
edited tags
Sep
3
revised Time Capsule cryptography?
edited tags
Sep
3
wiki created timed-release description
Sep
3
wiki created timed-release excerpt
Sep
3
revised Is it possible to make time-locked encrytion algorithm?
retag per http://meta.crypto.stackexchange.com/questions/300/what-should-we-do-with-the-time-sensitive-tag
Sep
2
revised AES CTR with similar IVs and same key
texify, list formatting, minor copyedits
Sep
2
revised Is it possible to translate a piece of language into your own without knowing the language?
edited tags
Sep
2
comment Is it possible to translate a piece of language into your own without knowing the language?
Ps. Obligatory Wikipedia link: en.wikipedia.org/wiki/Decipherment
Sep
2
comment Is it possible to translate a piece of language into your own without knowing the language?
Although it's kind of close, I don't think this question is really on topic for Cryptography Stack Exchange. You might have better luck with it on the History or Linguistics Stack Exchange sites. (That said, if someone else thinks it's on topic here and wants to answer it, I could change my mind.)
Sep
2
answered Initialization vector in symmetric-key encryption
Sep
2
comment Initialization vector in symmetric-key encryption
Related: Encryption with “constant” initialization vector considered harmful
Sep
1
comment How to renew keys for a statically-encrypted database
Actually, I see no fundamental reason why you couldn't replace, say, the last byte in the SIV tag with a key identifier, provided that you ignored that byte when verifying message authenticity. It would slightly decrease the nominal strength of the S2V (i.e. authenticity) part of SIV, but not significantly. Of course, the resulting scheme would no longer be standard SIV, which might be a concern. (It's always nice to be able to say that you're using a standard encryption method.)
Sep
1
awarded  Synonymizer
Sep
1
reviewed No Action Needed Feedback requested on a method of posting a message without revealing the author