Balance between Performance and Security in IPI-based Key Schemes using Heartbeats

The heartbeat interval is known to be random and unique to each individual. For secure communication between biometric sensors (e.g., attachable/implantable medical devices) within a body area network, various IPI-based key agreement schemes have been recently proposed in which such cardiac cycles are a source of trust. However, such existing works were difficult to compare fairly due to various error correction rates, different security strengths and key agreement times. For this reason, we roughly classify the existing IPI-based key agreement schemes into two types according to whether or not all (Type 1) or some (Type 2) of the output bits of the error correction code are transmitted. In this paper, we analyze the characteristics of each classified type and then we find out that Type II provides generates the secret key relatively quickly under a valid security strength in an emergency situation.