A simple project that provides an interface to encrypt and decrypt strings using the next algorithms:
- AES
- Blowfish
- Cast
- DES
- Idea
- Rc2
- Rc4
- Seed
The project uses PoCo C++ libraries, they have a nice and easy to use interface for OpenSSL.
I am studying the OpenSSL and it is a little tricky, PoCo C++ makes the job easier.

http://sourceforge.net/projects/easy-encryptor/