Chunxiang Gu Yuefei Zhu YaJuan Zhang An ID-Based Optimistic Fair Signature Exchange Protocol from Pairings. 9-16 2005 conf/cis/2005-2 CIS (2) http://dx.doi.org/10.1007/11596981_2 db/conf/cis/cis2005-2.html#GuZZ05