Akihiro Yamamura Takashi Kurokawa Junji Nakazato Threshold Anonymous Group Identification and Zero-Knowledge Proof. 370-384 2007 conf/acisp/2007 ACISP http://dx.doi.org/10.1007/978-3-540-73458-1_27 db/conf/acisp/acisp2007.html#YamamuraKN07