Research On Proxy Blind Signature With Message Recovery

The information industry expands greatly due to the rapid development of communication technology and computer science, information communication increases sharply in both scale and efficiency. The interconnected information network brings great convenience to people’s work and life, while the digital and informational way of life becomes a normal mode. As a resource that contains important resources in modern life, electronic data if of great potential economic and social values. Digital signature is one of the most efficient techniques that can guarantee the security of information. Due to different application circumstances, researchers propose many specially used digital signatures such as proxy signature, blind signature and proxy blind signature.The notion of proxy blind signature is brought up by Lin et al. in2000. Proxy blind signatures have both the features of proxy signatures and blind signatures, possess the properties like unlinkability, unforgeability, anti-repeatability and can help reduce storage and communication space. It helps the user to get the signature of a message from the proxy signer appointed by the original signer while makes sure that the proxy signer could neither get any content of the message, nor could he relate the concrete process of signing the message to a specific signature. Proxy blind signatures are being used in the areas which require functions such as blindability and proxy. It has many practical applications such as e-bank, e-voting, e-auction and e-check. The proxy blind signature is being thought highly of and widely researched in recent years. Many proxy blind signature schemes with extended properties are being proposed. However, by now, none of the schemes can fully fill the requirements of the practical application. More researches on the design of proxy blind signature schemes with specific application requirements and on the efficiency and security are expected.In this paper, we focus on the study of proxy blind signatures. Firstly, we introduce the background, development, security and construction mode of proxy blind signatures. Then, after analyzing the usual error mode of the present proxy blind signatures, we propose a proxy blind signature scheme of our own corresponding to specific applications, such as the publishing of e-cash and e-coupons of commercial organizations. Our main work is as follows: (1) We propose a new identity-based proxy blind signature scheme from pairings with expanded property under trusted PKG, and give the security proofs in detail. The property of message recovery enables verifier to complete signature validation and message recovery in one logical step. Compared with the present schemes, our scheme is more efficient and can be applied in e-cash.(2) Under untrusted PKG, we discuss the security problems of the id-based proxy blind signature scheme, and give the related definitions of proxy blind signature scheme with message recovery.(3) In the actual applications, there is no trusted party in business activities. Based on the existed schemes, we propose a new proxy blind signature scheme of message recovery without a trusted PKG for the first time, give the corresponding security proofs and analyze the efficiency of the protocol.