Evaluation of wavelet based ECG steganography system by using Percentage Residual Difference (PRD) measurements

Remote healthcare monitoring and Point of Care (PoC) based systems are widely used for managing diagnostic information of patients. These systems introduce many threats such as privacy, security data integrity, reliability, accuracy, etc. issues. In this paper, a new technique is introduced for solving the problem of privacy and security issues. In proposed method, ECG steganography technique using Discrete Wavelet Transforms (DWT) is implemented. This method is based on encryption and decryption techniques. Encryption method is used to hide the patient information inside the ECG signal by using scrambling matrix and shared key and produces the watermarked ECG signal. Decryption method is used to extract the patient secret information from the ECG signal by using same shared key and scrambling matrix. For evaluating the diagnosability, Percentage Residual Difference (PRD) and extracted PRD measurements are analyzed. From the results, table are calculated that there is no difference between PRD of original ECG and extracted ECG so watermarked ECG is also used for diagnosis purpose. In this paper, Signal to Noise Ratio (SNR) of normal PRD and extracted PRD are calculated using different wavelets and we have concluded that sym20 wavelet gives better response from the results than any other wavelet.