H2H makes use of ECG (heartbeat data) as an authentication mechanism, ensuring access only by a medical instrument in physical contact with an IMD-bearing patient.
Based on statistical analysis of real-world data, we propose and analyze new techniques for extracting time-varying randomness from ECG signals for use in H2H.
We introduce a novel cryptographic device pairing protocol that uses this randomness to protect against attacks by active adversaries,
while meeting the practical challenges of lightweight implementation and noise tolerance in ECG readings.
Finally, we describe an end-to-end implementation in an ARM-Cortex M-3 microcontroller that demonstrates the practicality of H2H in current IMD hardware.