LibTomCrypt is a fairly comprehensive, modular and portable cryptographic
toolkit that provides developers with a vast array of well known published block
ciphers, one-way hash functions, chaining modes, pseudo-random number
generators, public key cryptography and a plethora of other routines.
LibTomCrypt has been designed from the ground up to be very simple to use. It
has a modular and standard API that allows new ciphers, hashes and PRNGs to be
added or removed without change to the overall end application. It features easy
to use functions and a complete user manual which has many source snippet
examples.

* Block Ciphers
    * Blowfish
    * XTEA
    * RC5
    * RC6
    * SAFER+
    * Rijndael (aka AES)
    * Twofish
    * SAFER (K64, SK64, K128, SK128)
    * RC2
    * DES, 3DES
    * CAST5
    * Noekeon
    * Skipjack
    * Anubis (with optional tweak as proposed by the developers)
    * Khazad
    * KASUMI
    * SEED
...and more!