Partial encryption of ECG with reduced complexity and its FPGA implementation

Low-cost high-quality electrocardiographic diagnosis systems, Body Area Sensor Networks (BASNs) have become important for healthcare service providers but security and integrity of medical signal are not widely researched. This paper proposes a simple and novel partial encryption for the security of electrocardiographic data. The scheme is designed and developed on a configurable FPGA device and uses only half of the ECG data for encryption. Since the computation is done on reduced data, the computation cost is decreased and the processing speed of encryption process is augmented. The proposed hardware was implemented on Xilinx Virtex4 and Spartan3 FPGA giving maximum clock frequency of 286.8 MHz and 139.5 MHz respectively. The encrypted data along with the remaining unencrypted part of the data are used to construct the encrypted electrocardiographic signal giving it a noise like characteristics. This makes the encrypted signals uncorrelated to original ECG giving an average cross-correlation of −0...