scope:

This part of ISO/IEC 20009 specifies anonymous entity authentication mechanisms based on signatures using a group public key in which a verfier verifies a group signature scheme to authenticate the entity with which it is communicating, without knowing this entity's identity. This part of ISO/IEC 20009 provides - a general description of an anonymous entity authentication mechanism based on signatures using a group public key; - a variety of mechanisms of this type. This part of ISO/IEC 20009 describes - the group membership issuing processes; - anonymous authentication mechanisms without an on-line TTP; - anonymous authentication mechanisms involving an on-line TTP. Furthermore, this part of ISO/IEC 20009 also specifies - the group membership opening process (optional); - the group signature linking process (optional).