The security of traditional identity-based signatures wholly depends on the security of secret keys.Exposure of secret keys requires reissuing all previously assigned signatures.Based on this,to revoke private key leaks or malicious users in the signature scheme,an adaptive secure revocable identity-based signature over lattices is proposed,which provides an efficient revocation mechanism to revoke misbehaving or compromised users from the systems.The scheme is proved to be strongly Unforgeable against adaptive Chosen-message Attacks(sUFCMA)under Small Integer Solution(SIS)assumption.Security analysis results show that the proposed scheme not only can meet the security of revocable identity-based signature,but also can resist the quantum attack.
The security of traditional identity-based signatures wholly depends on the security of secret keys.Exposure of secret keys requires reissuing all previously assigned signatures.Based on this,to revoke private key leaks or malicious users in the signature scheme,an adaptive secure revocable identity-based signature over lattices is proposed,which provides an efficient revocation mechanism to revoke misbehaving or compromised users from the systems.The scheme is proved to be strongly Unforgeable against adaptive Chosen-message Attacks(sUFCMA)under Small Integer Solution(SIS)assumption.Security analysis results show that the proposed scheme not only can meet the security of revocable identity-based signature,but also can resist the quantum attack.
In the past, many ID-based signature (IBS) schemes based on the integer factorization or discrete logarithm problems were proposed. With the progress on the development of quantum technology, IBS schemes mentioned above would become vulnerable. Recently, several IBS schemes over lattices were proposed to be secure against attacks in the quantum era. As conventional public-key settings, ID-based public-key settings have to offer a revocation mechanism to revoke misbehaving or malicious users. However, in the past, little work focuses on the revocation problem in the IBS schemes over lattices. In this article, we propose a new revocable IBS (RIBS) scheme with short size over lattices. Based on the short integer solution (SIS) assumption, we prove that the proposed RIBS scheme provides existential unforgeability against adaptive chosen-message attacks. As compared to the existing IBS schemes over lattices, our RIBS scheme has better performance in terms of signature size, signing key size, and the revocation mechanism with public channels.
Certificateless signatures (CLS) are noticeable because they may resolve the key escrow problem in ID-based signatures and break away the management problem regarding certificate in conventional signatures. However, the security of the mostly previous CLS schemes relies on the difficulty of solving discrete logarithm or large integer factorization problems. These two problems would be solved by quantum computers in the future so that the signature schemes based on them will also become insecure. For post-quantum cryptography, lattice-based cryptography is significant due to its efficiency and security. However, no study on addressing the revocation problem in the existing lattice-based CLS schemes is presented. In this paper, we focus on the revocation issue and present the first revocable CLS (RCLS) scheme over lattices. Based on the short integer solution (SIS) assumption over lattices, the proposed lattice-based RCLS scheme is shown to be existential unforgeability against adaptive chosen message attacks. By performance analysis and comparisons, the proposed lattice-based RCLS scheme is better than the previously proposed lattice-based CLS scheme, in terms of private key size, signature length and the revocation mechanism.
In 2014, a new security definition of a revocable identity-based signature (RIBS) with signing key exposure resistance was introduced. Based on this new definition, many scalable RIBS schemes with signing key exposure resistance were proposed. However, the security of these schemes is based on traditional complexity assumption, which is not secure against attacks in the quantum era. Lattice-based cryptography has many attractive features, and it is believed to be secure against quantum computing attacks. We reviewed existing lattice-based RIBS schemes and found that all these schemes are vulnerable to signing key exposure. Hence, in this paper, we propose the first lattice-based RIBS scheme with signing key exposure resistance by using the left-right lattices and delegation technology. In addition, we employ a complete subtree revocation method to ensure our construction meeting scalability. Finally, we prove that our RIBS scheme is selective-ID existentially unforgeable against chosen message attacks (EUF-sID-CMA) under the standard short integer solutions (SIS) assumption in the random oracle model.
Inspired by Agrawal, Boneh and Boyen's identity-based encryption scheme, we proposed a post-quantum identity-based signature scheme from lattices. In this construction, two distinct trapdoors are used to find short bases. One trapdoor enables the real implementation to generate short bases for all lattices. The other trapdoor enables the simulator to generate short bases for all lattices. Moreover, the generating short bases are used to sample short vectors as signatures. Based on the hardness of the small integer solution (SIS) problem, the proposed scheme is proven to be strongly unforgeable against adaptive chosen-identity and adaptive chosen-message attacks without using random oracles. Compared with the existing strongly unforgeable identity-based signature schemes, our scheme has the advantages of full security and resistance to quantum computing attacks.
Identity-based signature schemes enable any pair of users to communicate securely and to verify each other's identity without exchanging private or public keys, without keeping key directories, and without using the services of a third party. However, when the number of users grows on a large scale, the generation, update, and distribution of keys become difficult problems, which limits its application range. Although some efficient RIBS scheme based on Computational Diffle-Hellam Problem(CDH) assumption has been proposed, few lattice-based RIBS do not achieve this realistic and efficient property. In this paper, we divide the Multi-party users keys update into three parts(Key Generation Center, Cloud Service Provider and user). In our scheme, a user's private key is composed of both an partial private key(by Key Generation Center), time update key(by Cloud Service Provider) and user's partial key(by user). The time update key is periodically updated by CSP and is transmitted over a public channel. our scheme is existential unforgeability against adaptive chosenmessage attacks in the random oracle based on the hardness assumption of Short Integer Solution(SIS) problem. Our scheme has better performance in terms of energy consumption, signature size, signing key size, and the revocation mechanism with public channels compared to other lattice-based signature scheme. As the underlying lattice problem is intractable even for quantum computers, our scheme would work well in the quantum age.
Blind signature allows a user to get a signature of a signer on an arbitrary message, and the verifier can convince that the signature is indeed signed by the signer without leaking any information about the message. This property is necessary when the user’s privacy needs protection, such as a bank bill, a trade secret, etc. As an alternative of public key infrastructure, the identity-based system can simplify the key management procedures in certificate-based public key systems. Inspired by the requirement of identity-based blind signature in the post quantum world, we research on identity-based blind signature based on hard lattice problems under the random Oracle model. We propose a construction built upon the blind signature by Rückert, and it is proved to be one-more unforgeable against selective identity and chosen message attacks (sID-CMA) and unconditionally blind. The proposed scheme has 2 moves, and its security can be reduced to the small integer solution (SIS) problem.