Michael Backes Birgit Pfitzmann Andre Scedrov Key-dependent Message Security under Active Attacks - BRSIM/UC-Soundness of Symbolic Encryption with Key Cycles. 421 2005 2005 IACR Cryptology ePrint Archive http://eprint.iacr.org/2005/421 db/journals/iacr/iacr2005.html#BackesPS05