ID-based Encryption Scheme Secure against Chosen Ciphertext Attacks

ID-based encryption allows for a sender to encrypt a message to an identity without access to a public key certificate. Based on the bilinear pairing, Boneh and Franklin proposed the first practical IDbased encryption scheme and used the padding technique of FujisakiOkamto to extend it to be a chosen ciphertext secure version. In this letter, we would like to use another padding technique to propose a new ID-based encryption scheme secure against chosen ciphertext attacks. The security of our scheme is based on the Gap bilinear Diffie-Hellman assumption in the random oracle model.