Pairing-Free Certificateless Signature with Security Proof

Wenhao Liu,Bin Hu,Qi Xie,Lidong Han,Shengbao Wang

doi:10.1155/2014/792063

Abstract

Since certificateless public key cryptosystem can solve the complex certificate management problem in the traditional public key cryptosystem and the key escrow problem in identity-based cryptosystem and the pairing computation is slower than scalar multiplication over the elliptic curve, how to design certificateless signature (CLS) scheme without bilinear pairings is a challenge. In this paper, we first propose a new pairing-free CLS scheme, and then the security proof is presented in the random oracle model (ROM) under the discrete logarithm assumption. The proposed scheme is more efficient than the previous CLS schemes in terms of computation and communication costs and is more suitable for the applications of low-bandwidth environments.

Highlights

In 2003, Al-Riyami and Paterson [1] first introduced the concept of certificateless public key cryptosystem (CL-PKC)
The basic idea of CL-PKC is to construct the user’s public/private key pair by combining a master key of the key generation center (KGC) with a random secret value generated by the user
CL-PKC eliminates the certificates in PKC and solves the key escrow problem in identity-based public key cryptosystem (ID-PKC)

Summary

Introduction

In 2003, Al-Riyami and Paterson [1] first introduced the concept of certificateless public key cryptosystem (CL-PKC). The first CLS scheme was proposed by Al-Riyami and Paterson [1] Following their works, Huang et al [2] pointed out that Al-Riyami et al.’s scheme is insecure against Type I adversary. All of them are vulnerable to the key replacement attack launched by a Type I adversary; what is more, they still need bilinear pairing computations. Gong and Li [24] pointed out the new scheme is insecure against the super adversary in the random oracle model, and they proposed a real CLS scheme and demonstrated that their scheme is secure against the supper adversary. We propose a new CLS scheme without bilinear pairings, and is provable secure in the random oracle model (ROM) under the discrete logarithm assumption.

Preliminaries

The Proposed CLS Scheme

Security Analysis

Performance Comparison

Conclusion