An efficient public key cryptosystem with a privacy enhanced double decryption mechanism

Abstract

A clue of double decryption mechanism was introduced at Eurocrypt '02 by Cramer and Shoup, and it was revisited at Asiacrypt '03 by Bresson, Catalano and Pointcheval. Previous double decryption schemes are designed based on Z na where n = pq for two primes, p and q. Note that, they use the Paillier's scheme as a primitive scheme to design a double decryption mechanism. In this paper, we propose an efficient public key scheme with double decryption mechanism based on Zpa9. Our scheme is more efficient than the previous schemes. Moreover, we review the previous schemes in a privacy point of view and propose a privacy enhanced double decryption scheme. © Springer-Verlag Berlin Heidelberg 2006.