The long-term security of public blockchains strictly depends on the hardness assumptions of the underlying digital signature schemes. In the current scenario, most deployed cryptocurrencies and blockchain platforms rely on elliptic-curve cryptography, which is vulnerable to quantum attacks due to Shor's algorithm. Therefore, it is important to understand how post-quantum (PQ) digital signatures behave when integrated into real blockchain systems. This report presents a blockchain prototype that supports multiple quantum-secure signature algorithms, focusing on CRYSTALS-Dilithium, Falcon and Hawk as lattice-based schemes. This report also describes the design of the prototype and discusses the performance metrics, which include key generation, signing, verification times, key sizes and signature sizes. This report covers the problem, background, and experimental methodology, also providing a detailed comparison of quantum-secure signatures in a blockchain context and extending the analysis to schemes such as HAETAE.
The long-term security of public blockchains strictly depends on the hardness assumptions of the underlying digital signature schemes. In the current scenario, most deployed cryptocurrencies and blockchain platforms rely on elliptic-curve cryptography, which is vulnerable to quantum attacks due to Shor's algorithm. Therefore, it is important to understand how post-quantum (PQ) digital signatures behave when integrated into real blockchain systems. This report presents a blockchain prototype that supports multiple quantum-secure signature algorithms, focusing on CRYSTALS-Dilithium, Falcon and Hawk as lattice-based schemes. This report also describes the design of the prototype and discusses the performance metrics, which include key generation, signing, verification times, key sizes and signature sizes. This report covers the problem, background, and experimental methodology, also providing a detailed comparison of quantum-secure signatures in a blockchain context and extending the analysis to schemes such as HAETAE.
This paper examines the growing threat that quantum computing presents to blockchain security. Core blockchain cryptographic frameworks, specifically the Elliptic Curve Digital Signature Algorithm and the Secure Hash Algorithm 256, are vulnerable to quantum algorithms. Both the Shor algorithm and the Grover algorithm are capable of breaking the Elliptic Curve Digital Signature Algorithm, enabling attackers to calculate private keys from public keys, while the Grover algorithm can also compromise hash-based systems that depend on brute-force methods, such as Proof-of-Work. On-chain analysis indicates that billions of dollars’ worth of crypto-assets are held in addresses susceptible to these quantum attacks. A proposed countermeasure is migration to Post-Quantum Cryptography, which incorporates quantum-resistant algorithms, such as CRYSTALS-Dilithium and Falcon. However, this migration introduces a trilemma among network security, decentralization, and performance. Post-Quantum Cryptography algorithms significantly increase transaction sizes and computational costs, which pose economic and technical challenges for large blockchain networks. The paper further discusses how the timeline for quantum advancements will be shaped by geopolitical competition, and how the catch-the-crop, decrypt-later strategy puts current data at risk from future quantum decryption. It emphasizes that active migration to Post-Quantum Cryptography is urgent, calling on stakeholders to prioritize system audits, transition to cryptographically flexible infrastructures, promote research into quantum-resistant solutions, and establish governance frameworks that enable prompt and decentralized upgrades.
The rapid advancement of quantum computing poses a fundamental threat to classical cryptographic mechanisms that underpin modern digital security. Shor’s algorithm can efficiently solve integer factorization and discrete logarithm problems, thereby breaking widely used public-key cryptosystems such as RSA, ECC, and Diffie–Hellman. Grover’s algorithm also reduces the effective security of symmetric encryption and hash functions by half. This paper provides a systematic analysis of the impact of quantum attacks on current cryptographic infrastructures, including TLS, digital signatures, and blockchain. We then review the state of post-quantum cryptography (PQC) as standardized by NIST, focusing on three leading candidates: CRYSTALS-Kyber for key encapsulation, and CRYSTALS-Dilithium and FALCON for digital signatures. Through simulation using the Open Quantum Safe (liboqs) library on a standard x86_64 platform, we measure key generation time, encryption/signing speed, decryption/verification latency, and key/signature sizes. Our results show that Kyber-768 achieves key generation in <0.1 ms and produces public keys of about 1.2 KB, while Dilithium-3 generates signatures of ~2.7 KB with verification times under 0.3 ms. Compared to RSA-2048 and ECDSA-P256, PQC algorithms offer competitive performance at the cost of larger key and signature sizes. Based on these findings, we propose a hybrid transition roadmap that combines classical and PQC algorithms in parallel, minimizing risk while maintaining backward compatibility. The paper concludes that organizations should begin immediate preparations for the post-quantum era, especially for data requiring long-term confidentiality.
The arrival of quantum computing poses a huge threat to conventional public key cryptography used in blockchain systems such as Bitcoin. To address this challenge, we proposes and evaluates a quantum resistant sidechain framework that integrates post quantum digital signature schemes and quantum key distribution (QKD) protocols with the Bitcoin mainchain. Using a Python simulation environment, the performance of multiple signature algorithms. ECDSA as a baseline measurement, Falcon, CRYSTALS-Dilithium, and SPHINCS+ were analyzed in combination with quantum communication protocols BB84, E91, and SARG04. Experimental results show that ECDSA remains the fastest baseline scheme but lacks quantum resistance, while SPHINCS+ provides the highest security with an expected overhead of 93.5 %. Among quantum protocols, BB84 achieved the best overall efficiency across transaction sizes. The optimal integration pairs were BB84 and CRYSTALS-Dilithium combination for speed, security balance and SPHINCS+ and E91 for maximum quantum resilience. These findings demonstrate the practical feasibility of deploying post quantum cryptographic components in Bitcoin compatible sidechains, paving the way for future blockchain networks that remain secure in the post quantum era.
Distributed systems are widely used in modern environments such as cloud platforms, Internet of Things (IoT) networks, smart grids, and blockchain-based systems. These platforms often require digital signatures to maintain trust between devices or users. When many signatures are shared at once, the size of the communication grows, and processing takes more time. This becomes a problem in applications where quick message verification is important. Classical digital signature schemes, such as Rivest-Shamir-Adleman (RSA) and Elliptic Curve Digital Signature Algorithm (ECDSA), are not safe against quantum attacks. Post-quantum cryptography offers better protection, but it often increases communication size and computation cost. This paper introduces a quantum-resistant model that supports signature aggregation and constant-time verification. The method is based on lattice-based techniques, using structures similar to CRYSTALS-Dilithium. By combining several signatures into a single aggregated form, the model reduces the time needed for verification and the overall communication overhead. The design is suitable for real-time applications, offering strong accuracy and faster message handling. Simulation results show that the proposed method performs better than recent approaches in multiple areas. The model achieves a low authentication time, high verification accuracy, reduced message size, and improved throughput. These benefits help meet the needs of distributed systems where speed, accuracy, and security must work together. The architecture is designed to be flexible for use in real-world deployments. Future directions include support for multi-party signing, adaptive quantum-safe policies, and integration with quantum co-processors. This research supports the development of secure and efficient communication frameworks that remain effective even in the presence of future quantum threats.
ABSTRACT The rapid advancement of quantum computing presents a significant threat to classical cryptographic systems, particularly RSA, whose security is based on the hardness of integer factorization. Shor’s algorithm demonstrates that large RSA keys can be efficiently broken in a quantum environment, raising concerns about the long-term reliability of traditional digital signatures. To address this, post-quantum cryptography (PQC) has emerged as a promising solution, with lattice-based schemes such as CRYSTALS-Dilithium3 gaining attention for their quantum resistance and efficiency. This study presents a comparative security and performance analysis of RSA and CRYSTALS-Dilithium3 digital signatures in the post-quantum era. The evaluation considers signature size, signing and verification speed, tamper detection capability, and resilience against classical and quantum attack models. Results highlight that RSA offers compact signature sizes but fails to provide integrity protection once subjected to simulated quantum attacks, while Dilithium3 ensures robust tamper detection, forward security, and cross-format verification across multiple document types. Despite larger signature sizes, Dilithium3 demonstrates superior verification speed and scalability, making it a viable candidate for post-quantum digital infrastructures. The findings emphasize the need for transitioning from classical to quantum-resistant cryptographic systems to ensure secure digital communication in the emerging quantum age. Keywords: Post-Quantum Cryptography, RSA, CRYSTALS-Dilithium3, Digital Signatures, Quantum Attacks, Tamper Detection, Performance Analysis
Public key cryptography plays a pivotal role in maintaining digital security and privacy, with its foundations built on the hardness of certain mathematical problems. However, the emergence of quantum computing threatens the security of current cryptographic systems, making the adoption of post-quantum cryptography (PQC) an urgent necessity. Digital signature schemes are essential components in secure communications, providing authentication, non-repudiation, and data integrity. This paper examines the state of post-quantum digital signature schemes across various cryptographic approaches, including lattice-based, code-based, multivariate polynomial-based, hash-based, symmetric-key-based, and isogeny-based systems, alongside advancements in Multi-Party Computation in the Head (MPC-in-the-head) schemes. The paper then explores application-specific signatures such as blind, undeniable, threshold, chameleon, aggregate, and ring signatures, explaining their main use cases and the existing post-quantum cryptographic classifications that support these constructions individually. Software implementations of selected prominent PQC digital signature schemes were carried out, and their performance was systematically analysed using metrics such as bandwidth consumption, latency, and computational efficiency. These results provide key observations regarding the suitability of different schemes for both resource-constrained and high-performance environments. Subsequently, a detailed literature review of implementations on embedded and hardware platforms is presented, focusing on ARM-based devices and FPGA accelerators to evaluate deployment feasibility beyond general-purpose processors. Based on the software and implementation-level findings, a comparative analysis across software, embedded, and hardware platforms is conducted to highlight architectural influences on performance, scalability, and practicality. Furthermore the cryptanalytic attacks on post-quantum digital signature schemes across various PQC classifications are examined in this paper, taking into account both classical and quantum adversarial models. To evaluate realistic security constraints, implementation-oriented vulnerabilities such as side-channel and fault-based attacks are also examined. In addition, the applicability of post-quantum digital signature schemes within TLS, IoT, and related practical deployment scenarios is analysed. The study also discusses possible directions for further investigation, focusing on the requirement for effective and expandable PQC systems that can satisfy changing cybersecurity requirements. In order to protect sensitive data in the digital era, this study emphasizes the need for implementing quantum-secure systems by fusing theoretical understandings with real-world applications.