A quantum cryptographic scheme for an audio file using quantum data encoding and quantum permutation pad

Abstract

Quantum computers can handle integer factorization and discrete logarithms more efficiently than their classical counterparts, which poses a threat to classical publickey cryptography. Also, quantum encryption systems and postquantum cryptography are gaining increasing attention due to the data vulnerability of classical systems. Hence, quantumnative encryption schemes are urgently needed. This work utilizes Quantum Permutation Pad (QPP), and it can be considered as an enhanced quantum extension of One Time Pad. A 2-qubit QPP is used to encrypt and decrypt an audio file using lowdepth gate permutations. The data file is segmented into 4bit blocks, each block is encoded as quantum states by using both basis and amplitude encoding, then encrypted with 2-qubit permutation circuits (depth ≤ 5). The key needed for the permutation index is distributed by using the Greenberger-Horne-Zeilinger (GHZ)-based Quantum Secret Sharing scheme prior to the encoding stage. IBM Qiskit simulations showed that QPP can be a lightweight encryption scheme for NISQ devices.