Detection of dishonest entities

This paper discusses mechanisms to identify dishonest users of services provided by a server in environments where identities of honest users must be kept as their secrets. An anonymous token based mechanism enables the server to identify dishonest users when dishonest events are detected while the users are receiving services, and a homomorhic anonymous token based one enables that even dishonest events can be detected only after the server completed their services and the users had left from the server. A linear equation based encryption algorithm that is used for implementing the above methods is also enhanced.