Novel Lossless Crypto-Compression Scheme for Medical Images

The transmission of patients' medical images over the network increases the instances of fraud involving the theft of patient information. Crypto-compression schemes are used to ensure high security for medical images and better compression, which is necessary for efficient network transmission. In this paper, I propose a new crypto-compression scheme and a novel lossless compression algorithm based on an improved version of the Lempel-Ziv 77 algorithm, which uses a sliding window of 64 KB in size, combined with a variation of the RLC algorithm. Unlike other methods, the proposed crypto-compression scheme employs a double level of security ensured by the ElGamal cryptosystem based on elliptic curves and the XChaCha20 stream cipher, thus providing more secure transmission of images. The crypto-compression scheme (ECX-LZ-RLC) proposed in this paper is compared with four modern crypto-compression methods, such as JPEG-AES, FMT-AES, JPEG-EC-LFSR, and EC-ElGamal. Experimental results show that ECX-LZ-RLC provides a higher compression rate and a better average crypto-compression time compared to other modern crypto-compression schemes, evaluated for grayscale and RGB medical images with different resolutions, taken from certain datasets.