Adaptive encryption using pseudo-noise sequences for medical images

The telemedicine involves the exchange of medical information among medical centres or the transmission of medical information from a patient to a medical center. Use of this application in the healthcare industry is increasing. Patient privacy is important, therefore, there is a great necessity to guarantee safe transmission of patient´s information. Pseudo noise sequences, such as the m-sequence and the Gold code, are easy to implement, have less correlation between the adjacent bits, and are very fast so they can be used for encryption purposes. In this paper, we propose a new algorithm based on the Gold code to permute the indexes of the pixels in a medical image. The permutation process was implemented adaptively according to the output values of the correlation and the NPCR. The results show a short processing time with a relatively high level of security.