Blockchain technology is facing critical issues of scalability, efficiency and sustainability. These problems are necessary to solve if blockchain is to become a technology that can be used responsibly. Useful quantum computers could potentially be developed by the time that blockchain will be widely implemented for mission-critical work at financial and other institutions. Quantum computing will not only cause challenges for blockchain, but can also be harnessed to better implement parts of blockchain technologies including cryptocurrencies. We review the work that has been done in the area of quantum blockchain and hybrid quantum–classical blockchain technology and discuss open questions that remain.

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量子和混合量子/经典区块链协议概述

区块链技术面临可扩展性，效率和可持续性的关键问题。这些问题对于解决区块链是否要成为可以负责任使用的技术是必不可少的。到区块链将广泛应用于金融和其他机构的关键任务工作时，可能会开发出有用的量子计算机。量子计算不仅会给区块链带来挑战，而且还能被用来更好地实施包括加密货币在内的部分区块链技术。我们回顾了在量子区块链和混合量子经典古典区块链技术领域已经完成的工作，并讨论了尚待解决的问题。