Quantum resource estimation of PRINCE and Midori Block Ciphers

With the continuous advancement of quantum technologies, the estimation of quantum resources necessary for quantum tasks becomes extremely important for optimization purpose. Quantum resource estimation approximates the amount of qubits, time, and the number of quantum gates required to complete a quantum computation. The difficulties in estimating quantum resources result the complexity of quantum systems. Precise estimates can be difficult because of the non-linear behaviour, entanglement effects, and resource limitations that might occur in quantum calculations. In this paper, the symmetric key cryptographic algorithms, PRINCE and Midori block ciphers are converted into the quantum circuit which will be used for applying Grover’s algorithm for exhaustive key search that reduces its security level from \(2^n\) $2^n$ bits to \(2^{\frac{n}{2}}\) $2^{\frac{n}{2}}$ bits. This paper discusses the construction of a quantum circuit for a substitution box (or S-box) using two level unitary matrix. The construction of substitution boxes in simple block ciphers as quantum circuits has lately been the subject of several publications, but they are limited to only 4-bit. A substitution box of size \(2^n\) $2^n$ bit, where n is a natural number, is converted into a quantum circuit using the two-level unitary matrix method.