Abstract: Anonymity is an effective approach to achieve privacy protection．Due to the illegal operation of a malicious user,anonymity requires to be disclosed in some applications．However there are two problems in the existing traceable anonymous schemes．The first one is that the rights of the administrator are too large．Secondly the overhead of storage and search for the relation between ID and a secret increases as the number of users increases．The paper proposed an efficient fair pseudonym management model．The model is composed of pseudonym issuance,pseudonymous application and joint tracking．The new partially blind signature protocol was given to ensure that CA takes part in pseudonym is-suance,however,it is unable to track．A secret sharing method was proposed to ensure that tracking authorities jointly disclose a pseudonym．The above two problems are solved effectively by the separation of issuance and tracking without storage and search for the relation between ID and secret．The analysis shows the model has the characteristic of anonymity,traceability,unforgeability,robustness and fairness．So it can be applied in anonymous communication with tracking requirements in Internet．Moreover,it can link up with traditional PKI technique well.

Key words: Anonymity,Pseudonymous management,Partially blind signature,Joint tracking