Pascal Junod Alexandre Karlov Arjen K. Lenstra Improving the Boneh-Franklin Traitor Tracing Scheme. 88-104 2009 Public Key Cryptography http://dx.doi.org/10.1007/978-3-642-00468-1_6 conf/pkc/2009 db/conf/pkc/pkc2009.html#JunodKL09