The successor to DES encryption approved by the US National Institute of Standards and Technology is called AES. The basis for AES is a wonderfully interesting block cypher called the Rijndael algorithm. If you are interested in Rijndael or block cypher encryption you can find out more about it here. A great place to find brief outlines of several of the more common types of cryptography can be found here. If you want to understand the basic structure of public key cryptography, this is a good place.
While I am on the subject of cryptography, let me post my public key information. Anyone interested in secure contact with my can use my publicly listed 1024 bit DSA key (ID: DC430CA6).