New secure partial encryption method for medical images using graph coloring problem

The traffic of digital images has been quickly increased in the network. Security of image processing became important for many sectors, namely for medical applications. Currently, the transmission of medical images is a daily routine. The large volume of data exchange has motivated the development of new methods to reduce the cost. Partial encryption is an approach to reduce the computational resources for huge volumes of multimedia. This paper introduces a new and secure approach, called graph coloring problem cryptography, to encrypt partially the medical images using the graph coloring problem (GCP). Before encrypting the medical images using advanced encryption standard algorithm, we use a GCP algorithm to localize and select some optimal positions of the pixels in the original images. Thus, the key of the cryptographic method is hard to be detected and extracted by the hackers. We get an acceptable percentage of the encrypted data for better security with a lower cost compared with the total image encryption.