Content-Based Medical Image Transmission Against Randomly-Distributed Passive Eavesdroppers
Mehdi Letafati, Hamid Behroozi, Babak Hossein Khalaj, Eduard Axel Jorswieck · 2021
In this paper, a content-aware medical image transmission scheme is investigated over a multiple-input single-output (MISO) channel in wireless healthcare systems. The multi-antenna-aided access point, as a source node, wishes to wirelessly send medical images of a patient to a trusted destination node, while multiple randomly-located totally passive and non-colluding eavesdroppers (Eves) try to wiretap the transmission. Considering the fact that not all regions of an image have the same importancy level from the security view-point, we first segment the image into two parts: the region of interest (RoI), which more likely contains important diagnostic information regarding the medical image— thus needs higher transmission reliability and confidentiality requirements; and the background (BG) of the image. Toward this end, by observing the legitimate link’s quality at each slot, we control the intercept probability (IP) at distributed Eves to be less than a desired threshold when transmitting RoI packets of image. In addition, with the aim of reinforcing system’s security, a fountain-based packet delivery is also adopted, where at each transmission slot, image packets are first encoded into fountain-like packets prior to being sent over the air. Considering the delay limits of a practical image transmission scheme, the secrecy will be achieved if the legitimate receiver obtains enough fountain packets before eavesdroppers. Simulation results conducted over a practical scenario of medical healthcare imaging illustrates that our proposed method can provide a reliable file delivery while maintaining image confidentiality and conforming to delay requirements of system.