Bilinear Pairings Based Convertible Authenticated Encryption Scheme with Provable Recipient

Convertible authenticated encryption (CAE) schemes are important cryptographic techniques which are applicable to many confidential business applications such as the contract signing and the credit card transactions. In case of a later dispute over repudiation, CAE schemes provide an arbitration mechanism for the public verification. Yet, previous proposed CAE schemes are primarily based on the discrete logarithm problem or the factorization problem and can not allow the designated recipient to prove himself as the real recipient. In this paper, we propose a bilinear pairings based efficient CAE scheme with provable recipient. The proposed scheme not only enables the designated recipient to prove that he is the real recipient if needed, but also has a nice signature conversion mechanism which can be solely done by the designated recipient without any extra computation or communication cost.