Verifiable and Secure Outsourcing Scheme of Exponentiation and Its Application in Wireless Sensor Network

Abstract

Every node in wireless sensor network has limited processing power, storage capacity and communication capability, so it is usually considered to be unsuitable for the use of public key cryptography technology. However, many research results indicated that some optimized publickey algorithms can provide much more security for wireless sensor networks (WSN) in recent years. As we known, every node in WSN often uses identity-based publickey signature to authenticate identity. However, modular exponentiation with computation cost is one of basic operations in identity-based public-key signature system, which can hamper the node to complete authentication. According to the features of WSN, we present two secure outsourcing schemes, in which nodes can securely outsource modular exponentiations to a single cloud server. The first one is a secure outsourcing scheme for fixed basevariable exponent exponentiation, and the second is for fixed exponent-variable base exponentiation. With our techniques, modular exponentiations can be efficiently computed by the user (node) with only O(1) modular multiplications, and our schemes are secure without any cryptographic assumptions. Based on our outsourcing scheme for modular exponentiations, we construct an outsourcing scheme for identity-based signature (IBS) in WSN, which is more suitable for WSN because it is superior in efficiency due to the reduction of nodes cost.