Secret Key-Awareness Secure in Certificateless Cryptography

Abstract

Abstract In certificateless cryptography protocol, public keys don’t be required certificates to guarantee their validity, so any other adversaries can replace users’ public keys. There are two security models: the weak security model prohibits the adversaries to query the decryption oracle of the ciphertexts under the public key chosen by the adversaries, and the more strong security model is asked to correctly answer the decryption oracle of this type of ciphertexts. As we well known, almost all certificateless cryptography protocols secure in the strong model are at the cost of the efficiency. In this paper, we introduce a new definition of secret key awareness security, and we can show a protocol secure in a weak security model is also secure in the strong security model, if it satisfies secret key awareness security simultaneously. We also give a concrete certificateless scheme secure in the strong security model.