Efficient Certificate-Based Signcryption Secure against Public Key Replacement Attacks and Insider Attacks

Abstract EN

Signcryption is a useful cryptographic primitive that achieves confidentiality and authentication in an efficient manner.

As an extension of signcryption in certificate-based cryptography, certificate-based signcryption preserves the merits of certificate-based cryptography and signcryption simultaneously.

In this paper, we present an improved security model of certificate-based signcryption that covers both public key replacement attack and insider security.

We show that an existing certificate-based signcryption scheme is insecure in our model.

We also propose a new certificate-based signcryption scheme that achieves security against both public key replacement attacks and insider attacks.

We prove in the random oracle model that the proposed scheme is chosen-ciphertext secure and existentially unforgeable.

Performance analysis shows that the proposed scheme outperforms all the previous certificate-based signcryption schemes in the literature.