Feasibility analysis of Inter-Pulse Intervals based solutions for cryptographic token generation by two electrocardiogram sensors

Heart-Based Biometric Protocols: A look back over almost two decades

“…When sensing the heart signal, apart from the technical difficulties due to, for instance, the noise of the signals; missed data during the gathering phase; delays, or; the bearer's movements [80], there are two main aspects to consider when using the heart signal in cryptographic protocols: 1) external alterations: it has been proven that parameters such as HRV can alter the peak detection algorithm [81], and; 2) length of the signal: it was thought that sensors have to gather for about 30 seconds [15,82,83,11] to generate 128 bits token. However, a recent study [84] increased that time to about 60 seconds to generate the same length token.…”

“…In particular, they rely on Bose-Chaudhuri-Hocquenghem (BCH) codes to synchronize the heart signal in different sensors. However, Ortiz et al [84] demonstrate that just using BCH algorithms are not enough to synchronize the signal. To do so, the authors used over 20 datasets from the Physionet repository with the signal being gathered from, at least, two devices.…”

“…Ortiz et al [84] implemented a fuzzy extractor based on BCH codes (see Figure 3). They used BCH (127,50,13), meaning that they could recover 10% of the errors during the transmission of the heart signal among devices.…”

“…• Related to the previous point, authors use many different environments to deploy their proposals. While most of the surveyed literature use theoretical or simulated environments, there are only a few works that deployed their solutions in real devices like a Raspberry Pi [146,84] and a manufacturer's pacemaker [202]. Thus, we argue for more realistic scenarios to test the experiments, being this more important when the target are IMDs.…”

Are the Interpulse Intervals of an ECG signal a good source of entropy? An in-depth entropy analysis based on NIST 800-90B recommendation

“…We took the public source code recently released by Ortiz et al [44] and made some slight modifications to get all the IPIs. This task was particularly computational demanding due to the amount of IPIs to generate and the number of databases involved in the experiment.…”