Crypt/OICQ version 1.0 ===================== This module implements the cipher used by OICQ instant messaging protocol, used by Tencent Technology Limited, China. INSTALLATION To install this module type the following: perl Makefile.PL make test su make install DEPENDENCIES None ACKNOWLEDGEMENT FreeOICQ developers reverse-engineered Tencent's Win32 client binaries and published their discovery on http://sourceforge.net/projects/foicq/. Among their codes are segments of assembly code for the OICQ cipher and login key generation. I identified the algorithm for login key generation to be MD5. Chen Peng reverse-engineered the rest of assembly codes created by FreeOICQ and identified the core cipher used by OICQ to be a weakened version of TEA, Tiny Encryption Algorithm. TEA was invented by David Wheeler and Roger Needham at Cambridge University. They recommend using 32 rounds. OICQ only uses 16 rounds. COPYRIGHT AND LICENCE Copyright (c) 2003 Shufeng Tan. All rights reserved. This package is free software and is provided "as is" without express or implied warranty. It may be used, redistributed and/or modified under the terms of the Perl Artistic License (see http://www.perl.com/perl/misc/Artistic.html)