D. Cash, D. Hofheinz, E. Kiltz, and C. Peikert. Annual International Conference on the Theory and Applications of Cryptographic Techniques, page 523--552. Springer, (2010)
D. Hofheinz, J. Müller-Quade, and R. Steinwandt. Computer Security -- ESORICS 2003, volume 2808 of Lecture Notes in Computer Science, page 61--84. Springer, (2003)