Optimized quantum computing technique to encrypt medical images

Quantum medical image encryption is one of the new methods to send medical images in an insecure communication channel. The proposed method is based on the flexible representation of quantum images which consists of two phases. In the first phase, the medical image is first interlaced using C-NOT gates and then the output of this phase is given to the second phase. In the second phase, one key is defined based on the logical mapping chaos function and the medical image encryption operation is performed based on this key. The output of the second phase is an encrypted image that can only be decrypted by the receiver which has the key. The results of the study of criteria such as histogram, entropy, correlation coefficient of adjacent pixels and correlation diagram show good performance. The entropy value of the proposed method is 99.67 which shows the proposed algorithm has much better performance than previous work. The temporal complexity of the designed quantum circuits is O(n), while the temporal complexity of the previous work is equal to \({\text{O}}\left({2}^{2n}\right)\) $\text{O}\left(2^{2n}\right)$ , which indicates the fast implementation of the proposed algorithm.