Edge-based lightweight selective encryption scheme for digital medical images

Securing digital medical images is increasingly becoming a major concern due to the rapid growth of the amount of medical images transferred over a network and stored on the web servers. However, the enormous size of multimedia and the huge volume of exchanging medical images have motivated the development of low computational complexity methods. This paper presents a lightweight selective encryption scheme to encrypt the edge maps of medical images. The edge map is firstly extracted by an edge detection method. Then, a chaotic map is used to generate a large key space. We propose a one-time pad algorithm to respectively encrypt the significant detected image blocks. The experimental results have proven that the proposed encryption scheme provides an acceptable percentage of encrypted image data. It can also effectively perform image encryption and decryption in a lightweight manner, which makes the scheme a good candidate for real time applications. Moreover, the security analysis demonstrates that our scheme has a robust resistance against various security attacks.