To counter the threats posed by quantum computing attacks on blockchain systems, researchers have explored both post-quantum blockchain and quantum blockchain solutions. However, post-quantum blockchain typically relies on complex mathematical puzzles, which result in high computational complexity and, consequently, low operational efficiency. Conversely, quantum blockchain is entirely dependent on the quantum processing capabilities of its nodes, leading to significant consumption of quantum resources, high networking costs, and reduced practicality. To address these challenges, a blockchain framework based on a semi-quantum key distribution network, referred to as Semi-Quantum Blockchain (SQB), is proposed. SQB enables classical users to engage in transactions while ensuring the unconditional security provided by quantum cryptography, significantly reducing the costs associated with network formation. The security analysis demonstrates that SQB provides robust post-quantum security and significantly outperforms its peers in terms of quantum resource consumption and quantum communication efficiency, establishing it as a secure and efficient blockchain solution.
Liu et al. (2026) studied this question.