https://www.hex-rays.com/contests/2012/
The IDA_Signsrch Win32 plugin is a handy port of Luigi Auriemma's signature matching tool signsrch. It can scan the whole database and comment known byte sequences, e.g. standard encryption constants or compression dictionaries.
Our comments: Improved for speed, coming with a rich set of predefined signatures, and featuring a clever and efficient pattern-matching algorithm, IDA_Signsrch is a valuable addition to any reverse engineer.