the success rate can be increased by calculating more chains and/or tables. if you have a success rate of 50% with 2^57 values in your tables then you can raise that to 75% rate with 2^58 values and 100% with 2^64 values. If you have 2^54 values then with 128 keystream samples your success rate is 1/(2^64 / 2^54 / 2^7) = 12.5% The calculation is pretty simple. it is a bit simplified as it ignores collisions that do not result in chain merges. because we are calculating 1/128th of the keyspace those collisions should produce less than 1% duplicate values and do not change the overall picture very much.
On Wed, Dec 09, 2009 at 12:35:56PM +0330, p q wrote: > its been told that the success rate of the attack is 50 % . how to increase > this ? is there any indication during the generation of tables to help us > know how much more success rate is being achieved by how > many additional chains ? > _______________________________________________ > A51 mailing list > [email protected] > http://lists.lists.reflextor.com/cgi-bin/mailman/listinfo/a51 _______________________________________________ A51 mailing list [email protected] http://lists.lists.reflextor.com/cgi-bin/mailman/listinfo/a51
