Abstract
An efficient key agreement protocol for ensuring information security is proposed for sensors in a wireless body area network. Based on the uniqueness of the health information for each patient, physiological signals collected from the medical sensors on the patient's body are used for establishing secret key. The proposed protocol is efficient because it uses only simple operations, such as computing exclusive-or and hash value; no modular exponentiation nor other computationally intensive functions are needed. Furthermore, the proposed protocol does not need a trusted center, and hence it can be used in any networks without infrastructure support. There are two important features in the proposed protocol. It is well-konwn that the physiological data measured by each sensor may be slightly different. The first important feature of our protocol is that efficient data adjustment step is included in the protocol to overcome the difference of the data measured by each sensor. The second feature is that the secret key established by the proposed protocol is perfect secure. We show that the attackers cannot compute the value of the secret key because they do not have enough information to do it. Therefore, the proposed protocol can o er as a fundamental tool for the protection of a patient's privacy and let the patient have a good quality of health care.