Implementation of a quantum image watermarking scheme using NEQR on IBM quantum experience

Recently, several quantum image watermarking (QIW) schemes have been introduced, but they cannot be implemented in today’s quantum systems due to lack of sufficient number of qubits of these systems. Enhancing the quantum transmitter and receiver circuits of these QIW schemes by reducing their number of qubits without increasing their run-time complexity is highly desired. Therefore, in this paper, a new quantum transmitter and receiver circuit for one of the existing QIW schemes which uses the NEQR quantum image representation is designed. It uses the IBM quantum experience reset operation and our proposed multi-controlled NOT quantum gate named MCNOT-R. Moreover, the complexity analysis and simulation results demonstrate the proposed quantum transmitter and receiver circuits achieve lower circuit complexity in terms of the number of qubits than those of the other quantum circuits for implementing the same watermarking scheme. Furthermore, simulation results show that proposed quantum circuits provide admissible visual quality.