Parallel quantum addition for Korean block ciphers.

Malicious users using quantum computers can employ quantum attacks on modern cryptography algorithms. Grover's search algorithm, a well-known quantum algorithm, can reduce the search complexity of O (2 n) to 2 n for symmetric key cryptography with an n-bit key. To apply the Grover search algorithm, the target encryption process must be implemented in a quantum circuit. In this paper, we present optimized quantum circuits for Korean block ciphers based on ARX architectures. We adopt the optimal quantum adder and design it in parallel way. Compared to previous implementations, we provide performance improvements of 78%, 85%, and 70% in terms of circuit depth for LEA, HIGHT, and CHAM, respectively, while keeping the number of qubits and quantum gates minimum. The depth of a circuit is an important factor related to its execution time. Finally, we estimate the cost of the Grover key search for Korean block ciphers and evaluate the post-quantum security based on the criteria presented by NIST. [ABSTRACT FROM AUTHOR]