Development and analysis of oracle for the hibrid attack on a cryptographic system NTRU using a quantum search algorithm

Due to the development of quantum computing, there is a need for the development and analysis of cryptosystems resistant to attacks using a quantum computer (post-quantum cryptography algorithms). The security of many well-known post-quantum cryptosystems based on lattice theory depends on the complexity of solving the shortest vector problem (SVP). In the paper, a model of the quantum oracle which is required for the implementation of the hybrid quantum-classical algorithm for solving SVP is proposed and analyzed. For the public key post-quantum cryptosystem NTRU which is the finalist of the third round of the NIST competition, upper bounds for the number of qubits and the depth of the scheme are obtained. The bounds are based on the proposed model of the quantum oracle.