Research On Blockchain Based On Quantum Key Distribution

Blockchain is a decentralized distributed ledger platform.As an integrated application of distributed data storage,peer-to-peer network,consensus mechanism,cryptographic algorithm,blockchain has the characteristics of decentralization,traceability,antimodification and so on.In recent years,the demand for diversified application scenarios has contributed to the rapid development of blockchain technology.Subsequently,most blockchain platforms,including Bitcoin,Ethereum and Hyperledger Fabric,gradually emerge.The security of its system is mainly safeguarded by the hash function and the public key cryptography algorithm based on large number decomposition or discrete logarithm problem in classical cryptography.However,with the emergence of quantum computers,the above-mentioned blockchain platforms are under the threat of quantum computing attack represented by Shor algorithm and Grover algorithm,which causes significant threats to the data security of blockchain and is a critical problem that restricts the application of blockchain to multiple scenarios.To solve the problem of quantum computer attack on classical blockchain,there are usually two solutions: blockchain based on post-quantum algorithm or quantum blockchain based on quantum properties,with the former still depending on computational security.This paper mainly centers on the blockchain based on quantum key distribution.It proposes an unconditional secure signature(USS)scheme and Byzantine fault-tolerant consensus mechanism and redesigns the blockchain architecture to ensure that the blockchain platform can run safely and reliably.The main research contents are as follows:1.To solve the security threat of public key digital signature,this paper proposes a MH-USS(Multilinear Hash-Unconditionally Secure Signature)signature scheme based on Quantum Key Distribution(QKD)and multilinear hash function family.In this scheme,quantum keys are distributed through QKD network,messages and signatures are transmitted through classical network,and the simplified USS signature scheme is adopted as the main framework,combined with the family of multiple linear hash functions,to generate a new MH-USS scheme.This signature scheme has the characteristics of unforgeability,nonrepudiation and transferability.Moreover,this scheme can be implemented on existing equipment and has high practical value.2.In view of the relatively low consensus efficiency of the classical Byzantine fault-tolerant consensus mechanism PBFT,this paper proposes the QS-BFT(Quantum Secured-Byzantine Fault Tolerance)consensus mechanism.By adding "fast-standard" consensus mode and allowing nodes to vote on empty blocks,the system communication times are reduced and the view conversion process is avoided.It has been proved that this scheme not only guarantees the safety and liveness,but also effectively reduces message complexity and improves consensus efficiency.The simulation and performance test for this scheme indicate that the throughput of this scheme is higher and the delay is lower compared with the PBFT consensus mechanism which is based on the MH-USS signature scheme.3.The blockchain system is designed to be suitable for the above-mentioned scheme.Firstly,the blockchain architecture is designed based on the MH-USS signature scheme and the QSBFT consensus mechanism.And the data layer,network layer and consensus layer of the blockchain are described in detail.Secondly,the design scheme of the system is realized.Finally,the performance test and comparison show that the blockchain system model is effective and feasible.This scheme has sufficient theoretical value and practical significance to ensure the safe and reliable operation of the blockchain.