New record in the number of qubits for a quantum implementation of AES

Frontiers in Physics

Physics

Qiaoyan Wen¹  Fei Gao¹  Sujuan Qin¹  Zhenqiang Li² 

[1] State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, Beijing, China;State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, Beijing, China;Henan Key Laboratory of Network Cryptography Technology, Zhengzhou, China;

关键词: AES;    S-box;    quantum circuit;    multiplication inversion;    number of qubites;   

DOI  :  10.3389/fphy.2023.1171753

 received in 2023-02-22, accepted in 2023-03-13,  发布年份 2023

来源: Frontiers

【 摘 要 】

Optimizing the quantum circuit for implementing Advanced Encryption Standard (AES) is crucial for estimating the necessary resources in attacking AES by the Grover algorithm. Previous studies have reduced the number of qubits required for the quantum circuits of AES-128/-192/-256 from 984/1112/1336 to 270/334/398, which is close to the optimal value of 256/320/384. It becomes a challenging task to further optimize them. AimTaking aim at this task, we find a method for how the quantum circuit of AES S-box can be designed with the help of the automation tool LIGHTER-R. Particularly, the multiplicative inversion in F28, which is the main part of the S-box, is converted into the multiplicative inversion (and multiplication) in F24, then the latter can be implemented by LIGHTER-R because its search space is small enough. By this method, we construct the quantum circuits of S-box for mapping |a⟩|0⟩ to |a⟩|S(a)⟩ and |a⟩|b⟩ to |a⟩|b ⊕ S(a)⟩ with 20 qubits instead of 22 in the previous studies. In addition, we introduce new techniques to reduce the number of qubits required by the S-box circuit for mapping |a⟩ to |S(a)⟩ from 22 in the previous studies to 16. Accordingly, we synthesize the quantum circuits of AES-128/-192/-256 with 264/328/392 qubits, which implies a new record.

【 授权许可】

Unknown   
Copyright © 2023 Li, Gao, Qin and Wen.