Indistinguishable against adaptive chosen ciphertext attack secure public key cryptosystem with double trapdoor decryption mechanism

Abstract

ABSTRACTPublic key cryptography is an important technique to resolve the security issues in computer communication networks. In some scenarios, a public key cryptosystem with double trapdoor decryption mechanism is desired. Previous known public key cryptosystems with double trapdoor decryption mechanism achieve no standard semantic security goals against adaptive chosen ciphertext attacks and were shown vulnerable to some attacks. In this paper, two new problems, the generalized RSA problem and the computational generalized RSA problem, are introduced, and the equivalence of the standard RSA problem and the computational generalized RSA problem is proven. Accordingly, on the basis of the computational generalized RSA problem, a public key cryptosystem with double trapdoor decryption mechanism, called GenRSA, is presented. We prove the GenRSA's indistinguishability security against adaptive chosen ciphertext attack under the computational generalized RSA intractability assumption and in the random oracle model. Copyright © 2013 John Wiley & Sons, Ltd.