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Topic
Board Beginners & Help
Re: FREE to enter 0.2 BTC Raffle
by
spoorancher
on 31/05/2013, 18:59:21 UTC
There is a system for picking giveaway winners that is random, fair, and verifiable. Put the list of entries in a text file, sort it randomly, and then add some salt at the end. Number each entry, starting with 0. Post a hash of the file to the thread for all to see. Then get a trusted third party, like an uncontroversial hero member, to post a random number, preferably a few orders of magnitude larger than the number of entries. The trusted third party must attest that he has not seen the contents of the text file. For appearances' sake the trusted third party should also not have entered the giveaway. Mod the random number by the number of entries; this is your selector. The entry corresponding to the selector is the giveaway winner. Post the contents of the text file in such a way that the entrants can reproduce the hash.

For example, this could be the list of entries:

boba
spork
nikto
azrael

Here's the text file (secret):

0 nikto
1 boba
2 spork
3 azrael
g3qnuqnjkfrenfduvrbequig5q34b/,mcsm,/hachm,/atm,/a

The hash (public):

MD5 (giveaway.txt) = f139f1c4069cfa99022a2fbea534431b

Trusted third party "weeboo" says he has not seen the secret and has no conflict of interest. He provides the number 42.

Post the secret file. 42 mod 4 is 2, so the winner is spork.