Secure medical image encryption with Walsh-Hadamard transform and lightweight cryptography algorithm

It is important to ensure the privacy and security of the medical images that are produced with electronic health records. Security is ensured by encrypting and transmitting the electronic health records, and privacy is provided according to the integrity of the data and the decryption of data with the user role. Both the security and privacy of medical images are provided with the innovative use of lightweight cryptology (LWC) and Walsh-Hadamard transform (WHT) in this study. Unlike the light cryptology algorithm used in encryption, the hex key in the algorithm is obtained in two parts. The first part is used as the public key and the second part as the user-specific private key. This eliminated the disadvantage of the symmetric encryption algorithm. After the encryption was performed with a two-part hex key, the Walsh-Hadamard transform was applied to the encrypted image. In the Walsh-Hadamard transform, the Hadamard matrix was rotated with certain angles according to the user role. This allowed the encoded medical image to be obtained as a vector. The proposed method was verified with the results of the number of pixel change rates and unified average changing intensity measurement parameters and histogram analysis. The results showed that the method is more successful than the lightweight cryptology method and the proposed methods in the literature to solve security and privacy of the data in medical applications with user roles.