Liang Cai Xiaohu Yang Chun Chen Design and Implementation of a Server-Aided PKI Service (SaPKI. 859-864 2005 conf/aina/2005 AINA http://doi.ieeecomputersociety.org/10.1109/AINA.2005.150 db/conf/aina/aina2005.html#CaiYC05