Joint Steganography-Source-Channel Coding for Wireless Physiological Signal Transmission

In this paper, we propose a novel Joint Steganography-Source-Channel Coding (JS²C²) scheme for scalable physiological signal transmission in wireless networks. Our goal is to secure patient's confidential data in medical signal by using Unequally Steganography Embedding and progressively transmit it by Joint Source-Channel Coding, limiting the extent of end to end distortion in the received signal, while abating transmission energy. The main contribution of this paper lies in the inherently joint design of the physiological signal steganography coding and transmission by taking advantage of the unequal importance among different segments of the physiological data. Higher steganography coding level and more robust source-channel coding will protect those highly important segments of the physiological data. Therefore, data integrity and transmission efficiency can be achieved in a resilient way. Simulation results demonstrate that USE attains low distortion (Wavelet-based Weighted Percent Root-mean-squared Difference, i.e. WWPRD <; 0.45 %) as well as high correlation between cover and stego data. Furthermore, low end-to-end Mean-Square-Error (MSE) indicates strong imperceptibility of stego data and ascertains that physiological signal remains diagnosable after JS²C².

I. Introduction

In the last few years, the importance of physiological signal communication has been augmented many fold. While communicating patient's confidential information over the noisy channel, it is imperative to ensure that security is maintained. Moreover, the reduction of the transmission energy and end to end distortion are also indispensable. To upheld the security of confidential information, steganography is a promising technology. To condense the transmission energy by increasing the density of effective data and diminishing the redundancy, data compression plays a crucial role in communication. In addition, the use of error correction is vital for reliable communication, in which appropriate channel coding is used to correct erroneous bits and minimize end to end distortion due to noisy channel. However, the communication efficiency decreases due to channel coding since it adds redundancy to the transmitted information bits. There are various Unequal Error Protection (UEP) strategies have already been researched within the framework of communication and information theory. However, to the best of our knowledge, UEP is never applied in the domain of steganography. We are among the first to exploit the diversity of significance of physiological signal for steganography. In addition, Forward Error Correction (FEC)-based rate allocation in formulation of the Joint Steganography-Source-Channel Coding scheme for UEP-based scalable physiological signal transmission is proposed. Fig. 1.

Reliable and energy efficient secure ECG transmission scheme