Yanjiang Yang Shuhong Wang Feng Bao Jie Wang Robert H. Deng New efficient user identification and key distribution scheme providing enhanced security. 697-704 2004 23 Computers & Security 8 http://dx.doi.org/10.1016/j.cose.2004.08.005 db/journals/compsec/compsec23.html#YangWBWD04