A Photoplethysmography Signal Encryption Approach Based on the Modular Derivative and Langton’s Ant

In this work, a photoplethysmography signal encryption/decryption approach is presented. The modular discrete derivative and Langton’s Ant encrypt signals obtained from a contact-less heart rate estimation method. On the one hand, the modular discrete derivative efficiently hides the information of the signals. On the other hand, the Langton’s Ant, a cellular automaton, incorporates a high key space. Thus, through statistical tests, performance against attacks analysis, and security tests, a secure and trustworthy encryption method applied to photoplethysmography signals is evaluated.