| Abstract | The certificate-based cryptosystems is traditional way in providing the system parameters. Identity-based cryptography is more efficient than certificate-based cryptosystems. Each user in identity-based cryptography uses any arbitrary string that uniquely identifies him as his public key. This paper proposes a new identity-based tripartite signcryption scheme based on the elliptic curve discrete logarithm problem. The proposed id-based tripartite signcryption scheme does not use the bilinear pairings in both the Signcryption and unsigncryption phases. The proposed scheme used to reduce the communication over head when three entities wants to communicate securely as in authentication protocol in GSM and in e-commerce. The proposed scheme satisfies various desirable security properties. Also, the performance of the proposed scheme is tested. |