Cryptlib by Peter Gutmann is a security toolkit that allows even less experienced programmers to add strong encryption and authentication services to their programs, security features that are becoming more and more indispensable. The library attempts to hide the low-level details of encryption/decryption and authentication from programmers, allowing them to quickly make their projects more secure. Some of the symmetric encryption (private key) and authentication algorithms that cryptlib supports include the following:

· AES (Rijndael)
· Blowfish
· DES, 3DES
· RC2, RC4, RC5

The following hash algorithms are available in the library:

· MD2, MD4, MD5
· RIPEMD-160
· SHA

It offers services such as:

· S/MIME
· SSL/TLS
· ssh

It features various hashed message authentication code algorithms:

· HMAC-MD5, HMAC-SHA, HMAC-RIPEMD-160

Finally, asymmetric (public/private key) encryption algorithms such as the following are available:

· Diffie-Hellman, DSA, RSA

cryptlib can also be used with a variety of crypto devices (for example, Fortezza cards and Smart cards).

The library is free if used in personal, freeware, or shareware projects. The library is written in C. ActiveX and C++ wrappers are provided. The project is OSI Certified Open Source Software.