Anonymity-enhanced pseudonym system

Abstract

Pseudonym systems allow users to interact with multiple organizations anonymously by using pseudonyms. Such schemes are of significant practical relevance because it is the best means of providing privacy for users. In previous works, users transact with a organization by demonstration of possession of a credential issued by the organization or relationship with another credential. However, the information that a user has a credential from a specific organization compromises privacy of the user. In the present paper, we give a formal definition of practical pseudonym system in which the level of privacy provided can be chosen be according to security policies. © Springer-Verlag Berlin Heidelberg 2003.