Abstract:
Camellia algorithm is a block cipher algorithm widely used in the world, which has the characteristics of high security, high efficiency of software and hardware implementation. In order to use such cryptographic algorithms on the hardware platform of quantum computing, the realization of their quantum circuits must first be considered from a comprehensive perspective. Combining the structural characteristics of the Camellia algorithm, the quantum resource consumption of the algorithm under the quantum circuit model is given, including the number of qubits, the number of general quantum logic gates, the depth of the quantum circuit, and the product value of the number of qubits of the circuit and the depth of T. First, using the improved Itoh-Tsujii algorithm, Gaussian elimination method, and inversion over finite fields, the quantum implementation of the algorithm S-box is optimized. Secondly, according to the design characteristics of the linear part of the round function, a quantum optimization implementation scheme of the key expansion structure is given, which reduces the use of auxiliary qubits to a certain extent. On this basis, using the method of calculating the constant parameter Hamming weight, the CNOT gate is converted into a Pauli-X gate to reduce the consumption of quantum resources. And using the improved zig-zag structure to combine the main components of the algorithm, a quantum circuit implementation of the Camellia algorithm is given. Finally, the scheme gives the quantum resources consumed by the Camellia algorithm under three different versions of keys. Compared with quantum circuit implementations of traditional methods and other algorithms, the proposed scheme consumes less quantum resources. The proposed circuit will lay the foundation for the in-depth study of Camellia algorithm in quantum environment.