An important task for quantum cloud computing is to make sure that there is a real quantum computer running, instead of classical simulation. Here we explore the applicability of a cryptographic verification scheme for verifying quantum cloud computing. We provided a theoretical extension and implemented the scheme on a 5-qubit NMR quantum processor in the laboratory and a 5-qubit and 16-qubit processors of the IBM quantum cloud. We found that the experimental results of the NMR processor can be verified by the scheme with about $1.4\%$ error, after noise compensation by standard techniques. However, the fidelity of the IBM quantum cloud is currently too low to pass the test (about $42\%$ error). This verification scheme shall become practical when servers claim to offer quantum-computing resources that can achieve quantum supremacy.

量子云计算的一项重要任务是确保有一台真正的量子计算机在运行，而不是经典模拟。在这里，我们探讨了密码验证方案在验证量子云计算方面的适用性。我们对该方案进行了理论扩展，并在实验室的 5 量子比特核磁共振量子处理器和 IBM 量子云的 5 量子比特和 16 量子比特处理器上实现了该方案。我们发现核磁共振处理器的实验结果可以通过该方案进行验证，大约$1.4\%$误差，通过标准技术进行噪声补偿后。然而，IBM量子云的保真度目前太低，无法通过测试（大约$42\%$错误）。当服务器声称提供可以实现量子霸权的量子计算资源时，该验证方案将变得实用。