Block cipher/External Links

AES links

 * NIST page, official page for the AES standard
 * AES Lounge, extensive information, including tables of cryptanalytic results and links to hardware implementations.
 * software implementations from Helger Lipmaa
 * software implementations from Bran Gladwin

Homepages for block ciphers

 * Blowfish
 * Twofish
 * Serpent
 * RC5 and RC6
 * MARS
 * Hasty Pudding

Other links

 * Block Cipher Lounge, once an excellent index of current research, now out-of-date
 * Literature survey on S-box design