An system for allowing a computer network site to recognize an anonymous user without revealing the identity of the user. The system involves generating a user alias based on the user's identity and the computer network site such that it is computationally difficult to determine the user's identity from...http://www.google.com.au/patents/US6463533?utm_source=gb-gplus-sharePatent US6463533 - System for generating site-specific user aliases in a computer network
