International Association
for Cryptologic Research

The advancement of large-scale quantum computers poses a threat to the security of current encryption systems. In particular, symmetric-key cryptography significantly is impacted by general attacks using the Grover's search algorithm. In recent years, studies have been presented to estimate the complexity of Grover's key search for symmetric-key ciphers and assess post-quantum security. In this paper, we propose a depth-optimized quantum circuit implementation for ARIA, which is a symmetric key cipher included as a validation target the Korean Cryptographic Module Validation Program (KCMVP). Our quantum circuit implementation for ARIA improves the depth by more than 88.2% and Toffoli depth by more than 98.7% compared to the implementation presented in Chauhan et al.'s SPACE'20 paper. Finally, we present the cost of Grover's key search for our circuit and evaluate the post-quantum security strength of ARIA according to relevant evaluation criteria provided NIST.