Bessie C. Hu Duncan S. Wong Zhenfeng Zhang Xiaotie Deng Certificateless signature: a new security model and an improved generic construction. 109-126 2007 42 Des. Codes Cryptography 2 http://dx.doi.org/10.1007/s10623-006-9022-9 db/journals/dcc/dcc42.html#HuWZD07