Informed symmetric encryption algorithm for DICOM medical image based on N-grams

The Internet has evolved to become an essential tool for communication. However, this communication is increasingly involved in strategic issues related to the security of information being exchanged. Transactions made through the network can be intercepted; therefore, it will be necessary to ensure the security of such information. Cryptographic techniques can play a very important role to address the problem associated with secure image transfer through communication networks. Hence, a limited number of encryption / decryption methods have been proposed to date. These methods are mainly based on key generation; using either a symmetrical or asymmetrical means, where both have drawbacks in terms of slowness (as in the case of asymmetric systems) or secret keys security (as in the case of symmetric systems). In this paper, we propose a new approach for generating symmetric keys for image encryption / decryption, whereby the medical images (area of interest) use an informed process based on a technique that has been demonstrated on textual analysis called N-grams. We denote by an informed cryptosystem, a system that generates keys based on the original image characteristics to be encrypted. The results obtained are very significant and are detailed in this paper.