A novel trusted third party based signcryption scheme

To prevent man-in-the-middle attack, Diffie-Hellman first proposed the concept of the session key exchange protocol, in which the author remove the long term keying material at the end of the session. In our scheme, we apply the session key concept of Diffie-Hellman for cloud computing in the presence of the Trusted Third Party (TTP). Our proposed scheme provides SEVEN security properties by using the session key exchange protocols as symmetric. In our scheme, TTP becomes free from a burden of activities, like to encrypt the requests (R_i) of the Cloud Service Users (CSUs) and to decrypt the services (S_i) of the Cloud Service Providers (CSPs) again and again. By using S Performance (EP) for Elliptic Curve Point Multiplication (ECPM), Hash (H), Inversion (Inv), Exclusive oR (XoR), Encryption (Enc), and Decryption (Dec) is (87.5%, 62.5%, 57.14%), (87.5% and 75%), (75%), (97.82% and ≤?1%), (92.85%) and (50%) respectively. The security requirements of our scheme are; data integrity, data confidentiality, authenticity, non-repudiation, forward secrecy, unforgeability, and untraceability. Our proposed scheme also outperformed performance in terms of flexibility, reliability, and efficiency as compared to existing schemes.