RC5Simple - it's easy crossplatform C++ library for encrypt/decrypt arrays and files.
Encrypt method is RC5-32/12/16 with CBC.
RC5Simple work only with not big data (up to 4Gb in 32 bit mode).
Support Compilation to 32 bit and 64 bit architecture.
Official page: http://webhamster.ru/site/page/index/articles/projectcode/157 (RU)