Secure Certificateless Signature with Revocation in the Standard Model

Abstract

Certificateless public key cryptography is very attractive in solving the key escrow problem which is inherent in identity- (ID-) based public key cryptography. In the past, a large number of certificateless cryptographic schemes and protocols were presented, but a secure certificateless signature in the standard model (without random oracles) is still not accessible until now. To the best of our knowledge, all the previously proposed certificateless signature schemes were insecure under a considerably strong security model in the sense that they suffered from outsiders’ key replacement attacks or the attacks from the key generation center (KGC). In this paper, we propose a certificateless signature scheme without random oracles. Moreover, our scheme is secure under the strong security model and provides a public revocation mechanism, called revocable certificateless signature (RCLS). Under the standard computational Diffie-Hellman assumption, we formally demonstrate that our scheme possesses existential unforgeability against adaptive chosen-message attacks.

Lattice-Based Revocable Certificateless Signature

“…The framework of RCLS scheme is identical to that of the RCLS schemes in [14,15]. In an RCLS scheme, there are three roles, namely, a key generation center (KGC), signers and verifiers.…”

“…By the security model of RCLS schemes in [14,15], adversaries have three types that are presented as follows.…”

“…Tseng and Tsai [10] presented the revocation method using public channel. In addition, two primitives (encryption and signature) in revocable certificateless public-key cryptography (RCL-PKC) were also proposed, such as revocable certificateless public-key encryption (RCL-PKE) schemes [11,12] and revocable certificateless signature (RCLS) scheme [13,14]. Furthermore, Hung et al [15] presented a short RCLS scheme.…”

A Revocable Certificateless Short Signature Scheme and Its Authentication Application

“…Recently, Tsai and Tseng (2015) and Shen et al (2013), independently, proposed a revocable certificateless public-key encryption (RCL-PKE) scheme based on Tseng and Tsai's revocable ID-based encryption with public channels (Tseng and Tsai, 2012). Tsai et al (2014aTsai et al ( , 2014b further proposed a revocable hierarchical ID-based encryption scheme. Afterwards, Sun et al (2014) and Tsai et al (2014aTsai et al ( , 2014b, respectively, proposed a revocable certificateless signature (RCLS) scheme in the random oracle model and in the standard model.…”

“…Tsai et al (2014aTsai et al ( , 2014b further proposed a revocable hierarchical ID-based encryption scheme. Afterwards, Sun et al (2014) and Tsai et al (2014aTsai et al ( , 2014b, respectively, proposed a revocable certificateless signature (RCLS) scheme in the random oracle model and in the standard model. However, the signature sizes of all the RCLS schemes are more than one group element.…”