Yevgeniy Dodis Aggelos Kiayias Antonio Nicolosi Victor Shoup Anonymous Identification in Ad Hoc Groups. 609-626 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3027&spage=609 2004 conf/eurocrypt/2004 EUROCRYPT db/conf/eurocrypt/eurocrypt2004.html#DodisKNS04