A Fuzzy Trust Model for Public Key Distribution in Body Area Networks

Abstract

It is now possible to implant a network of sensors inside the human body for monitoring the human body functions and the surrounding environment. In a body area network (BAN), the confidentiality and integrity of the sensitive health information are particularly important. The key establishment is thus a fundamental security service in BANs. To guarantee validity of the key and avoid misbehavior of self-ish nodes, we propose a fuzzy trust model for public key queries in BANs. Every user accesses the public keys of other nodes from those trusted neighbors rather than all of its neighbors. The proposed trust model uses fuzzy sets to calculate every node’s trust value. Our trust model exploits multiple metrics rather than a single metric, and converts them into a single numerical ranking. We perform an extensive evaluation of the proposed approach. The results indicate that our trust model can not only identify abnormal nodes’ behaviors, but can also reduce query traffic while improving the reliability of the returned public keys.