Preserving the Confidentiality of Clinical Images Through a Chaotic Low-Power Hardware Platform and DNA Coding-Based Encryption

Image encryption is a robust method to secure information transmission over public, unprotected networks. Thanks to their complex dynamics, chaotic systems are gaining interest for encryption scheme development. This paper presents a novel method to generate pseudorandom sequences designing a compact and cost-effective circuit that mimics the dynamics of the logistic map. This hardware platform employs a standard microcontroller to turn the raw chaotic time series into balanced binary sequences, made mutually-orthogonal one to the other through cross-correlation calculations. The resulting binary codes passed all statistical tests in the Institute of Standards and Technology (NIST) SP 800-22 suite, with success rates up to 99.6%. Here, we discuss the integration of the proposed hardware platform into an image encryption system aimed at securing clinical communications. We exploited the unique properties of the chaotic codes to implement a DNA-inspired image encryption algorithm. Robustness was evaluated against four clinical images of skin ulcers, one for each severity class (Wound Bed Preparation standard). An automated data classification procedure confirmed that the encryption and decryption processes do not degrade the diagnostic content of the images. Six security and robustness tests were also passed successfully. We thus present an economic hardware solution, amenable to integration into standard communication platforms, delivering security and enabling novel data protection methods in clinical environments.