Bo Qin Qianhong Wu Willy Susilo Yi Mu Publicly Verifiable Privacy-Preserving Group Decryption. 72-83 2008 Inscrypt http://dx.doi.org/10.1007/978-3-642-01440-6_8 conf/cisc/2008x db/conf/cisc/inscrypt2008x.html#QinWSM08