Liang Cai Xiaohu Yang Chun Chen Architecture of a Server-Aided Signature Service (SASS) for Mobile Networks. 819-826 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3421&spage=819 2005 conf/icn/2005-2 ICN (2) db/conf/icn/icn2005-2.html#CaiYC05