Proposing a method to design secure digital signature scheme on the ring structure Zn

Abstract—In this paper, we propose a method to design signature scheme on ring structure with residual classes modulo composite. At the same time, we develop several new digital signature schemes that are more secure, with faster signature generation than ElGamal digital signature scheme and its variants. Furthermore, our proposed signature scheme has overcome some weaknesses of some published signature scheme of the same type, which are built on ring structure. Tóm tắt—Trong bài báo này, chúng tôi đề xuất một phương pháp thiết kế lược đồ chữ ký trên cấu trúc vành các lớp thặng dự theo modulo hợp số, đồng thời phát triển một số lược đồ chữ ký số mới an toàn hơn, tốc độ sinh chữ ký nhanh hơn so với lược đồ chữ ký số ElGamal cùng với những biến thể của nó. Hơn nữa, lược đồ chữ ký do chúng tôi đề xuất cũng khắc phục được một số nhược điểm của một số lược đồ chữ ký cùng loại, được xây dựng trên cấu trúc vành.

Provably Secure Lattice-Based Self-Certified Signature Scheme

Digital signatures are crucial network security technologies. However, in traditional public key signature schemes, the certificate management is complicated and the schemes are vulnerable to public key replacement attacks. In order to solve the problems, in this paper, we propose a self-certified signature scheme over lattice. Using the self-certified public key, our scheme allows a user to certify the public key without an extra certificate. It can reduce the communication overhead and computational cost of the signature scheme. Moreover, the lattice helps prevent quantum computing attacks. Then, based on the small integer solution problem, our scheme is provable secure in the random oracle model. Furthermore, compared with the previous self-certified signature schemes, our scheme is more secure.

Constructing efficient and secure batch signature schemes

In ordinary signature schemes, such as RSA, DSA, ECDSA, the signing process is performed only for a single message. Due to performance issues, in some contexts, the above solutions will become unsuitable if a party needs to sign multiple messages simultaneously. For example, in the authenticated key exchange protocols based on signatures between client and server, the server is expected to handle multiple key exchange requests from different clients simultaneously. Batch signing is a solution that generates signatures for multi-messages simultaneously with a single (ordinary) signature generation. In this article, we will consider some of the existing batch signing solutions and point out a few of their weakness. To deal with these problems, the paper also proposes two secure types of batch signature schemes, but still ensures the same efficiency as the existing batch signing solution.

Guessing Bits: Improved Lattice Attacks on (EC)DSA with Nonce Leakage

The lattice reduction attack on (EC)DSA (and other Schnorr-like signature schemes) with partially known nonces, originally due to Howgrave-Graham and Smart, has been at the core of many concrete cryptanalytic works, side-channel based or otherwise, in the past 20 years. The attack itself has seen limited development, however: improved analyses have been carried out, and the use of stronger lattice reduction algorithms has pushed the range of practically vulnerable parameters further, but the lattice construction based on the signatures and known nonce bits remain the same.In this paper, we propose a new idea to improve the attack based on the same data in exchange for additional computation: carry out an exhaustive search on some bits of the secret key. This turns the problem from a single bounded distance decoding (BDD) instance in a certain lattice to multiple BDD instances in a fixed lattice of larger volume but with the same bound (making the BDD problem substantially easier). Furthermore, the fact that the lattice is fixed lets us use batch/preprocessing variants of BDD solvers that are far more efficient than repeated lattice reductions on non-preprocessed lattices of the same size. As a result, our analysis suggests that our technique is competitive or outperforms the state of the art for parameter ranges corresponding to the limit of what is achievable using lattice attacks so far (around 2-bit leakage on 160-bit groups, or 3-bit leakage on 256-bit groups).We also show that variants of this idea can also be applied to bits of the nonces (leading to a similar improvement) or to filtering signature data (leading to a data-time trade-off for the lattice attack). Finally, we use our technique to obtain an improved exploitation of the TPM–FAIL dataset similar to what was achieved in the Minerva attack.

New hybrid signature schemes with increasing level of resistance

Post-quantum cryptography is becoming an increasingly popular topic for research around the world. The global cryptographic community is on the verge of standardizing new post-quantum algorithms. The world’s largest organizations conduct their own research in this direction. In this article, two hybrid schemes are proposed. They are constructed on generalized methods of increasing resistance of authentication schemes. Hybrid schemes consist of a combination of two independent signature schemes, one of which is the well-known classical asymmetric electronic signature scheme and another one is post-quantum scheme. Thus, this paper suggests the combining Crystals-Dilithium scheme with Rabin scheme and Elgamal scheme respectively. The paper also provides estimates of public key and signature lengths. Conclusions are drawn about the expediency of using generalized methods of combining with such kind of schemes.

Anti-Quantum Lattice-Based Ring Signature Scheme and Applications in VANETs

Message authentication is crucial because it encourages participants to accept countermeasures and further transmit messages to legitimate users in a network while maintaining the legitimacy of the identity of network members. An unauthorized user cannot transmit false messages to a given network. Although traditional public key cryptography is suitable for message authentication, it is also easy to manage and generate keys, and, with the expansion of an entire network, the system needs a lot of computing power, which creates additional risks to network security. A more effective method, such as ring signature, can realize this function and guarantee more security. In this paper, we propose an anti-quantum ring signature scheme based on lattice, functionality analysis, and performance evaluation to demonstrate that this scheme supports unconditional anonymity and unforgeability. After efficiency analysis, our scheme proved more effective than the existing ring signature schemes in processing signature generation and verification. The proposed scheme was applied to VANETs that support strong security and unconditional anonymity to vehicles.

Enhanced quantum signature scheme using quantum amplitude amplification operators

Quantum signature is the use of the principles of quantum computing to establish a trusted communication between two parties. In this paper, a quantum signature scheme using amplitude amplification techniques will be proposed. To secure the signature, the proposed scheme uses a partial diffusion operator and a diffusion operator to hide/unhide certain quantum states during communication. The proposed scheme consists of three phases, preparation phase, signature phase and verification phase. To confuse the eavesdropper, the quantum states representing the signature might be hidden, not hidden or encoded in Bell states. It will be shown that the proposed scheme is more secure against eavesdropping when compared with relevant quantum signature schemes.

Identity-Based Linkable Ring Signature on NTRU Lattice

Although most existing linkable ring signature schemes on lattice can effectively resist quantum attacks, they still have the disadvantages of excessive time and storage overhead. This paper constructs an identity-based linkable ring signature (LRS) scheme over NTRU lattice by employing the technologies of trapdoor generation and rejection sampling. The security of this scheme relies on the small integer solution (SIS) problem on NTRU lattice. We prove that this scheme has unconditional anonymity, unforgeability, and linkability under the random oracle model (ROM). Through the performance analysis, this scheme has a shorter size of public/private keys, and when the number of ring members is small (such as N ≤ 8 ), this scheme has a shorter signature size compared with other existing latest lattice-based LRS schemes. The computational efficiency of signature has also been further improved since it only involves multiplication in the polynomial ring and modular operations of small integers. Finally, we implemented our scheme and other similar schemes, and it is shown that the time for the signature generation and verification of this scheme decreases roughly by 44.951% and 33.503%, respectively.

Digital signature schemes with strong existential unforgeability

Digital signature schemes (DSS) are ubiquitously used for public authentication in the infrastructure of the internet, in addition to their use as a cryptographic tool to construct even more sophisticated schemes such as those that are identity-based. The security of DSS is analyzed through the existential unforgeability under chosen message attack (EUF-CMA) experiment which promises unforgeability of signatures on new messages even when the attacker has access to an arbitrary set of messages and their corresponding signatures. However, the EUF-CMA model does not account for attacks such as an attacker forging a different signature on an existing message, even though the attack could be devastating in the real world and constitutes a severe breach of the security system. Nonetheless, most of the DSS are not analyzed in this security model, which possibly makes them vulnerable to such an attack. In contrast, a better security notion known as strong EUF-CMA (sEUF-CMA) is designed to be resistant to such attacks. This review aims to identify DSS in the literature that are secure in the sEUF-CMA model. In addition, the article discusses the challenges and future directions of DSS. In our review, we consider the security of existing DSS that fit our criterion in the sEUF-CMA model; our criterion is simple as we only require the DSS to be at least secure against the minimum of existential forgery. Our findings are categorized into two classes: the direct and indirect classes of sEUF-CMA. The former is inherently sEUF-CMA without any modification while the latter requires some transformation. Our comprehensive review contributes to the security and cryptographic research community by discussing the efficiency and security of DSS that are sEUF-CMA, which aids in selecting robust DSS in future design considerations.