The Efficient CCA Secure Public-Key Encryption Scheme

Abstract

The security and efficient public key encryption algorithm is an important technology guarantee for security of information systems.This paper uses an idea of trapdoor commitment function to protect ciphertext integrity,thus presents a provable public-key encryption(PKE) scheme in the standard model,which is secure against adaptive chosen ciphertext attacks(CCA).The new encryption scheme is very efficient: Compared to the previously most famous scheme by Cramer and Shoup(CS98) it has 20% shorter public keys and 80% shorter secret keys;compared to the scheme by BMW05 it has shorter public/secret keys and has tighter and simpler security reduction.The new encryption scheme supports public ciphertext integrity verification,has short public/secret keys,and its security proved reduces to the Gap Hashed Diffie-Hellman(GHDH) assumption tightly.