Cryptology ePrint Archive: Report 2019/1245

Observations on the Quantum Circuit of the SBox of AES

Jian Zou and Yongyang Liu and Chen Dong and Wenling Wu and Le Dong

Abstract: In this paper, we propose some improved quantum circuits to implement the Sbox of AES. Our improved quantum circuits are based on the following strategies. First, we try to find the minimum set of the intermediate variables that can be used to compute the 8-bit output of the Sbox. Second, we check whether some wires store intermediate variables and remain idle until the end. And we can reduce the number of qubit by reusing some certain wires. Third, we try to compute the output of the Sbox without ancillas qubits, because we do not need to be clean up the wires storing the output of the Sbox. This operation will reduce the number of Toffoli gates. Our first quantum circuit only needs 26 qubits and 46 Toffoli gates, while quantum circuit proposed by Langenberg \emph{et al.} required 32 qubits and 55 Toffoli gates. Furthermore, we can also construct our second quantum circuit with 22 qubits and 60 Toffoli gates.

Category / Keywords: secret-key cryptography / quantum circuit, AES, Sbox, Grover’s algorithm

Date: received 24 Oct 2019

Contact author: fzuzoujian15 at 163 com

Available format(s): PDF | BibTeX Citation

Version: 20191024:094154 (All versions of this report)

Short URL: ia.cr/2019/1245