Security Analysis of Classical and Post-Quantum Blockchains

In recent years, the emergence of quantum computing has created substantial problems to the security of cryptographic methods often utilized in blockchain technology. As quantum computers become more powerful, the possibility of them breaking classical cryptography algorithms such as ECDSA grows, forcing researchers to look for quantum-resistant alternatives. Post-quantum cryptographic algorithms, such as Falcon, have emerged as possible alternatives for long-term blockchain security. This study examines the performance and security of classical (ECDSA) and post-quantum (Falcon) blockchains under a variety of attack scenarios, including DDoS, replay, and Sybil attacks. Our research will evaluate the computational and resource needs of several cryptographic approaches, as well as examine how these infrastructures respond under various attack situations and emphasize the trade-offs between higher security and resource consumption. Our results show that, while post-quantum blockchains are more resistant to quantum computing threats, they need much more CPU and memory than their classical equivalents. This increased resource requirement affects scalability and efficiency, especially in high-load scenarios. Despite their resistance to quantum attacks, post-quantum blockchains are still vulnerable to traditional attack vectors, as demonstrated by the significant computing cost seen throughout our testing. These research results underscore the need of balanced blockchain systems that successfully handle the trade-offs between security and performance.