Hierarchical Identity based Group Signature with enhanced privacy of the signers

Supporting the privacy of the signer with controlled anonymity is an important feature of group signatures. However, since the group manager controls the anonymity of signer, the group manager can be a threat to the privacy of honest signers. Recently, OneCard service is popular in many ID card systems. In order to protect the singer’s privacy against third party one can use group signature to verify that the user is a valid user for a specific service. If One Card service includes different levels of traceability requirements, then it must contain different sets of group signatures in order to preserve the privacy of the signer against the group manager. In this paper we propose a hierarchical identity based group signature scheme and introduce a way to provide enhanced privacy protection for signers against the group manager efficiently in the services with different levels of traceability requirements. Key–Words: Group signature, Hierarchical ID based signature, traceability, privacy of signer