Jian Weng Shengli Liu Kefei Chen Dong Zheng Weidong Qiu Identity-Based Threshold Key-Insulated Encryption without Random Oracles. 203-220 2008 CT-RSA http://dx.doi.org/10.1007/978-3-540-79263-5_13 conf/ctrsa/2008 db/conf/ctrsa/ctrsa2008.html#WengLCZQ08