Yutaka Kawai Shotaro Tanno Takahiro Kondo Kazuki Yoneyama Noboru Kunihiro Kazuo Ohta Extension of Secret Handshake Protocols with Multiple Groups in Monotone Condition. 160-173 2008 WISA http://dx.doi.org/10.1007/978-3-642-00306-6_12 conf/wisa/2008 db/conf/wisa/wisa2008.html#KawaiTKYKO08