Reversible data hiding in ecg signals based on histogram shifting and thresholding

With the development of communication and networking technologies, the telemedicine system has become more and more popular due to its distance unawareness, low cost to the patients, long-term physiological data recording and real-time diagnosis. In order to protect the private information of patients when transmiting data in the telemedicine system, data hiding technique is used by hiding the patient confidential information in the ECG signals. In this paper, a reversible data hiding scheme for patient privacy protection is proposed. An integer-to-integer Harr wavelet transform for the integer ECG signal is adopted to guarantee the reversibility. A histogram shifting and thresholding scheme is carefully designed to adaptively embed private data according to the given capacity and recover both the private data and the original ECG signal without any distortion. Simulation results show that the proposed method outperforms the existing method.