Distributed PKG ID based signcryption

An identity-based signature scheme allows any pair of users to communicate securely and to verify each other´s signatures without exchanging public key certificates. For achieving both confidentiality and authenticity simultaneously, signcryption schemes are used. This paper puts forward a new efficient construction for signcryption scheme which is based on inverse bilinear Diffie Hellman problem and Discrete Logarithmic problem. The proposed scheme is secure against chosen ciphertext attack and has least complexity in terms of computational complexity as compared to earlier proposed schemes. The proposed scheme also caters the inherent problem of Key Escrow where private key generator (PKG) is not trusted by the use of concept of distributed PKG.