Publication

Abstract : ECG signals tagged with secret information are transferred through wireless communication channel in remote health monitoring applications. To hide secret information, the proposed steganography system uses ECG signal as cover data. The watermarked data (grey scale image or ECG signal) is transformed into 2D binary matrix (QR code), to enhance security of the steganography process. The Base64 encoding technique converts unsigned integer values to alphanumeric cypher text, which is then turned into a 2D binary matrix (QR code) through a QR code generator/reader. The threshold selection algorithm is used to select the coefficient position, and the pixel swapping technique is employed to incorporate watermark data into the selected location. Signal degradation is minimized by selecting coefficient locations are near to zero. The imperceptibility of the watermarked ECG signal is evaluated using performance metrics such as Peak Signal to Noise Ratio (PSNR), Percentage Residual Difference (PRD), Correlation Coefficient (CC), and Structural Similarity Measure Index (SSIM). Bit Error Rate is another metric used to evaluate the quality of extracted watermark data (BER). The watermarked signals imperceptibility is found to be good and is within the ideal value. Increase in payload capacity has increased signal deterioration. The steganography scheme has no BER, and the reconstructed signal is identical to the cover ECG signal.