Experimental cryptographic verification for near-term quantum cloud computing

Xi Chen; Bin Cheng; Zhaokai Li; Xinfang Nie; Nengkun Yu; Man-Hong Yung; Xinhua Peng

doi:10.1016/j.scib.2020.08.013

Experimental cryptographic verification for near-term quantum cloud computing

Sci Bull (Beijing). 2021 Jan 15;66(1):23-28. doi: 10.1016/j.scib.2020.08.013. Epub 2020 Aug 12.

Authors

Xi Chen¹, Bin Cheng², Zhaokai Li¹, Xinfang Nie¹, Nengkun Yu³, Man-Hong Yung⁴, Xinhua Peng⁵

Affiliations

¹ Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China (USTC), Hefei 230026, China; CAS Key Laboratory of Microscale Magnetic Resonance, USTC, Hefei 230026, China; Synergetic Innovation Center of Quantum Information and Quantum Physics, USTC, Hefei 230026, China.
² Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China; Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China; Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China; Shenzhen Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
³ Centre for Quantum Software and Information, School of Software, Faculty of Engineering and Information Technology, University of Technology Sydney, NSW 2007, Australia. Electronic address: nengkunyu@gmail.com.
⁴ Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China; Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China; Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China; Shenzhen Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China. Electronic address: yung@sustc.edu.cn.
⁵ Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China (USTC), Hefei 230026, China; CAS Key Laboratory of Microscale Magnetic Resonance, USTC, Hefei 230026, China; Synergetic Innovation Center of Quantum Information and Quantum Physics, USTC, Hefei 230026, China. Electronic address: xhpeng@ustc.edu.cn.

PMID: 36654308
DOI: 10.1016/j.scib.2020.08.013

Abstract

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.

Keywords: NMR quantum computing; Quantum cloud computing; Quantum computation; Verification.