The advent of quantum computing presents significant challenges to current cryptographic systems, particularly those based on the Discrete Logarithm Problem (DLP), which underpins the security of many cryptocurrencies. In response, we propose a quantum-resistant adaptation of the Updatable Public Key (UPK) primitive in the Quisquis cryptocurrency protocol. This adaptation transitions from a DLP-based security model to one grounded in the Learning With Errors (LWE) assumption, which is believed to be secure against quantum attacks. Our LWE-based UPK scheme preserves the key advantages of Quisquis, including the ability to update public keys in a publicly verifiable manner while maintaining their indistinguishability from freshly generated keys. We discuss the challenges introduced by this transition, particularly the accumulation of noise during key updates, and outline future work to address these issues. Our work ensures that Quisquis remains a robust and efficient solution for privacy-preserving transactions in a post-quantum world.
The advent of quantum computing presents significant challenges to current cryptographic systems, particularly those based on the Discrete Logarithm Problem (DLP), which underpins the security of many cryptocurrencies. In response, we propose a quantum-resistant adaptation of the Updatable Public Key (UPK) primitive in the Quisquis cryptocurrency protocol. This adaptation transitions from a DLP-based security model to one grounded in the Learning With Errors (LWE) assumption, which is believed to be secure against quantum attacks. Our LWE-based UPK scheme preserves the key advantages of Quisquis, including the ability to update public keys in a publicly verifiable manner while maintaining their indistinguishability from freshly generated keys. We discuss the challenges introduced by this transition, particularly the accumulation of noise during key updates, and outline future work to address these issues. Our work ensures that Quisquis remains a robust and efficient solution for privacy-preserving transactions in a post-quantum world.
Modern public key cryptosystems rely on two assumptions regarding computational difficulty: the integer factorization problem (RSA) and the discrete logarithm problem (elliptic curve cryptography).These problems have stood the test of time for four decades of cryptanalysis.Yet, their algebraic and periodic nature makes them vulnerable to quantum algorithms, most notably Shor's algorithm (1994).This paper presents a detailed comparison between classical and quantum-resistant cryptographic systems with an emphasis on lattice-based systems.The Learning With Errors (LWE) problem and its variants (Ring-LWE, Module-LWE) do not have the same periodicity that makes problems like integer factorization and discrete logarithms susceptible to quantum algorithms.Furthermore, LWE problems have reductions from worst-case lattice problems and have mathematical proofs of quantum resistance.Due to the vulnerability of ECDSA algorithms for cryptocurrencies, it is estimated that current cryptocurrencies will no longer be secure once quantum computer technology matures within the next 10-30 years, potentially compromising holdings estimated at between $260 billion and $390 billion as of August 2026.The implications of cryptanalysis on public key cryptography systems motivate mathematical recommendations regarding the security of current cryptosystems and the need for a shift to post-quantum cryptographic standards.
In this work, we introduce a novel post-quantum public key encryption scheme over integers, leveraging a hybrid approach that combines large random numbers with the Learning With Errors (LWE) system. The scheme addresses the security challenges posed by quantum computing advancements, aiming to provide a robust solution resistant to quantum-based attacks. By using the unknown random number hardness assumption with enhancements to the traditional LWE framework and operating directly on integers, this approach ensures a high level of cryptographic security while maintaining computational efficiency. Extensive theoretical and experimental analyses demonstrate that the proposed encryption system achieves state-of-the-art performance: encryption execution time as low as2.45×10−5seconds, decryption time of4.47×10−5seconds, and an integrity check time of5.30×10−5seconds. Moreover, the ciphertext size is reduced to only 1330 bits while maintaining a 256 -bit security level, representing a significant reduction in storage requirements compared to conventional lattice-based approaches. These results confirm that our scheme not only provides strong quantum-resistant security guarantees but also delivers excellent efficiency and scalability, making it a viable candidate for secure communications in bandwidth-limited and resource-constrained environments in the quantum era.
The landscape of modern cryptography is fundamentally challenged by the advent of quantum computing. Current public-key cryptosystems, which form the bedrock of secure digital communication, rely on the computational hardness of problems such as integer factorization (RSA) and the discrete logarithm problem (ECC). However, Shor's algorithm, if implemented on a sufficiently powerful quantum computer, can efficiently break these schemes, rendering them insecure. This paper explores the critical transition from these classical number theory problems to lattice-based cryptography, presenting a comprehensive analysis of the motivations, theoretical underpinnings, and practical implications for forging post-quantum cryptographic security. We delve into the mathematical foundations of lattice problems, such as the Shortest Vector Problem (SVP) and Learning With Errors (LWE), which are believed to resist known quantum algorithms. Through a thorough literature review, we trace the evolution of cryptographic thought, detailing the vulnerabilities of pre-quantum schemes and the emergence of lattice-based constructions as leading candidates for post-quantum standardization. The methodology outlines a comparative theoretical analysis of security, efficiency, and robustness against both classical and quantum attacks. Results demonstrate the compelling advantages of lattice-based schemes in terms of provable security reductions and resistance to quantum threats, albeit with considerations for increased key and ciphertext sizes. The discussion highlights the challenges and opportunities in the deployment and standardization of these new cryptographic primitives, emphasizing their critical role in securing future digital infrastructures. This work concludes that lattice-based cryptography offers a robust and theoretically sound pathway to establishing enduring security in a quantum-threatened world.
The advent of quantum computing poses a significant existential threat to the security of contemporary public-key cryptographic systems, such as RSA and Elliptic Curve Cryptography (ECC), which underpin global digital communication and secure transactions. These systems rely on the computational hardness of problems like integer factorization and the discrete logarithm problem, which are efficiently solvable by Shor's algorithm on a sufficiently powerful quantum computer. This paper comprehensively rethinks the foundations of public-key cryptography by exploring ideal lattice-based schemes as a promising, quantum-secure alternative. We delve into the mathematical underpinnings of ideal lattices, particularly focusing on their compact representation and efficient arithmetic derived from polynomial rings. We elucidate how the conjectured hardness of ideal lattice problems, such as the Ring Learning With Errors (RLWE) problem and the Ideal Shortest Vector Problem (Ideal-SVP), provides robust security against both classical and quantum adversaries. Through a detailed analysis of their cryptographic properties, efficiency benefits, and security guarantees, we argue for the critical role of ideal lattices in forging the next generation of resilient public-key infrastructures. This research highlights the advantages of ideal lattices in terms of performance and security compactness, making them leading candidates in the ongoing standardization efforts for post-quantum cryptography.
The rapid development of quantum computers poses a significant threat to the majority of current authenticated key exchang protocols, designed on the hardness of large integer factorization and discrete logarithm problems. Therefore, it is imperative to develop secure and efficient quantum-resistant authenticated key exchang protocols. This paper designs a new public-key cryptographic scheme for identity authentication based on Ring Learning With Errors (RLWE) problem and error reconciliation mechanism. Based on the scheme, we further design a quantum-resistant authenticated key exchange protocol (AKE). This protocol is provably secure under the standard eCK model and achieves forward secrecy. Compared with other classic key exchange protocols based on the RLWE problem, our protocol shows comprehensive advantages in terms of security, computational complexity, and communication complexity.
Public key cryptography is widely used to secure transactions over the Internet. However, advances in quantum computers threaten to undermine the security assumptions upon which currently used public key cryptographic algorithms are based. In this paper, we provide a survey of some of the public key cryptographic algorithms that have been developed that, while not currently in widespread use, are believed to be resistant to quantum computing based attacks and discuss some of the issues that protocol designers may need to consider if there is a need to deploy these algorithms at some point in the future.