Haeryong Park Seongan Lim Ikkwon Yie Kitae Kim Junghwan Song Strong unforgeability in group signature schemes. 856-862 2009 31 Computer Standards & Interfaces 4 http://dx.doi.org/10.1016/j.csi.2008.09.019 db/journals/csi/csi31.html#ParkLYKS09