Ron Rivest

Ron Rivest is a cryptographer who teaches at MIT. He is probably best known as the "R" in RSA, co-inventor of of the most widely used public key encryption technique. Rivest is also one of the founders of RSA Laboratories, a company created to comercialise the RSA system which has since grown into one of the major players in the information security industry.

Among the things Rivest has designed (sometimes with collaborators), and the company has marketed, have been:
 * DES-X, an enhanced version of DES
 * a series of Message Digest (cryptographic hash) algorithms. Rivest's MD4 and MD5 have been widely used, as have other hashes whose design is heavily influenced by MD4, the NSA's SHA hashes and the European RIPE-MD. MD6 is an entrant in the Advanced Hash Standard contest.
 * a series of ciphers called RCn with "RC" for "Rivest Cipher" or perhaps "Ron's Code". RC4 is a very widely used stream cipher. RC6 was a finalist in the AES contest.