A New Public Key Encryption with Equality Test

We proposed a new public key encryption scheme with equality test (PKEET), which stands for a public key encryption scheme with comparable ciphertext. The equivalence among ciphertext under PKEET schemes can be verified without decryption. In some PKEET algorithms like Tang’s AoN-PKEET, which is called authorization-based PKEET, the equality test functionality is restricted to some authorized users: only users who own authorities are able to perform equality test functions. For the best of our knowledge, the authorities of all existing authorizationbased PKEET schemes are valid for all ciphertext encrypted under the same public key. Accurately, we propose a CBA-PKEET scheme following Tang’s AoN-PKEET scheme, which means a PKEET scheme with ciphertext-binded authorities (CBA). Each ciphertext-binded authority is valid for a specific ciphertext, rather than all ciphertext encrypted under the same public key. Then, we compare the features and efficiency between our CBA-PKEET and some existing authorization-based PKEET schemes. Finally, the security of CBA-PKEET is proved in the random oracle model based on the some hard problems.