Design and Analysis of Multi Receiver Signcryption Schemes on Elliptic Curves

Abstract

Multicast is an efficient means of information dissemination to a set of nodes. It has low utilization of bandwidth and communication resources as compare to unicast. Secure multicast preserves confidentiality and authenticity of information to legitimate group members, adopted in emerging commercialization of wireless applications. Elliptic curves cryptography has promising industrial attraction. National Security Agency (NSA) of USA purchased license of ECC from Certicom. It will use ECC in its cryptographic modernization initiative, which aims to replace about 1.3 million existing security equipments over the next 10 years. Public Key Infrastructure (PKI) is the most popular centralized and hierarchical infrastructure, consists of trusted third parties registration authority and certificate authority and provides solution for proving authenticity of public keys. Multi receiver signcryption ensure confidential and authenticated dissemination of information to multicast group member instead of multi recipient encryption and digital signature. It is attractive for stateful secure multicast to distribute and update session keys and stateless secure multicast to disseminate multicast messages. In this thesis, we proposed six multi-receiver signcryption schemes on elliptic curve in PKI setting. First, multi-receiver signcryption scheme has functionalities of confidential and authenticated multicast session key agreement and instant secure message communication. It is efficient in term of computation and communication cost and suitable for secure multicast communication. Second, multi receiver signcryption with forward secrecy has additional functionality of forward secrecy of messages. It ensures confidentiality even if an attacker has stolen the sender private key. Its low communication overhead could make this construction a better option for use in resource constrained secure multicast communication. xvii Third, multi receiver signcryption for firewalls has additional functionality of encrypted message authentication. It enables firewall to verify encrypted message without disclosing message contents and obtaining any secret parameter from the participants. In case of dispute judge can also verify the authenticity of ciphertext and solve the dispute with obtaining any secret parameter from the participants. Its security attributes and cost effectiveness makes it suitable choice for efficient and secure multicast firewalls applications. Fourth, generalized multi receiver signcryption scheme based on elliptic curves has functionality of digital signature or multi receiver encryption or multi receiver signcryption with single algorithm. Fifth, blind multi receiver signcryption scheme has additional functionality of sender anonymity. It has significance in applications as privacy preserving multicast communication; electronic voting and payment system to protect the sender privacy and guarantees the freedom of thoughts and freedom of opinion. Sixth, proxy multi receiver signcryption scheme has functionality of designated a proxy agent, who makes multicast communication on the behalf of original user. It has applications in privilege delegation mechanism, an essential service in modern enterprises and organizations to extend and operate business via designated agent due to temporal absence, lack of time or processing capability.