A Contractual Anonymity System

摘要

We propose, develop, and implement techniques forrnachieving contractual anonymity. In contractual anon-rnymity, a user and service provider enter into an anonym-rnity contract. The user is guaranteed anonymity and mes-rnsage unlinkability from the contractual anonymity sys-rntem unless she breaks the contract. The service providerrnis guaranteed that it can identify users who break therncontract. The significant advantages of our system arernthat 1) the service provider is not able to take any actionrntoward a particular user (such as revealing her identityrnor blacklisting her future authentications) unless she vi-rnolates her contract, 2) our system can enforce a varietyrnof policies, and 3) our system is efficient.