Harvard University There are a number of situations in the Internet where it would be useful to be able to have an application be able to send traffic to a destination without revealing the IP address of the destination to the source, or the IP address of the source to the destination, or both. One way to do this is to have a network resident set of servers which can forward packets, with encryption and decryption applied to their source and destination addresses when appropriate. We will call this server an anonymizing forwarder.