This paper introduces a new capability for group signatures called message-dependent
opening. It is intended to weaken the high trust placed on the opener; ie, no anonymity
against the opener is provided by an ordinary group signature scheme. In a group signature
scheme with message-dependent opening (GS-MDO), in addition to the opener, we set up
an admitter that is not able to extract any user's identity but admits the opener to open
signatures by specifying messages where signatures on the specified messages will be …

This paper introduces a new capability of the group signature, called message-dependent
opening. It is intended to weaken the higher trust put on an opener, that is, no anonymity
against an opener is provided by ordinary group signature. In a group signature system with
message-dependent opening (GS-MDO), in addition to the opener, we set up the admitter
which is not able to open any user's identity but admits the opener to open signatures by
specifying messages whose signatures should be opened. For any signature whose …