Enhancing digital communication security with wavelet transforms for efficient data encryption

In the modern telehealth, secure transmission of the signals of biomedical signals, notably electrocardiogram (ECG) data, is crucial. In this paper, we propose a new hybrid encryption scheme in wavelet domain using chaotic maps to protect the sensitive ECG signals. Then, it applies a discrete wavelet transform (DWT) to the ECG signals to decompose them into multi resolution sub bands to isolate important signal features and reduce redundancy. Next, there is utilization of a chaotic logistic map to produce a pseudo random key stream with the advantage of the map sensitivity to the initial condition for added security. By encrypting the wavelet coefficients of the ECG with the chaotic key stream combined with, the encrypted signal becomes noise like length and does not carry any medical information. Finally, we demonstrate the methodology on the standard MIT BHI arrhythmia ECG dataset as well as preprocess this data (median filtering and normalization) and extract features for completeness. Results of the experiments indicate that the proposed scheme displays nearby encryption ideal behaviour; ciphertext entropy ~7.99 bits, near zero plaintext and ciphertext correlation, similar to AES and superior to DES for a 30-minute ECG record, the execution time is in the order of tenths of a second.