Abstract
This paper presents a novel two-tier authentication and encryption scheme that explores the unique characteristics of Wireless Sensor Networks (WSN) in Healthcare Applications. The first phase authenticates among the sensor nodes of a Body Area Network (BAN) fused in a patient, where a U key is generated in a decentralized fashion. Based on the rule of separating user and platform credentials, U key approaches maximize security in a nontrusted environment. The second phase authenticates the data aggregation node elected among the sensor nodes of a patient with the base station in the vicinity to securely relay the U key as a session key. Encryption, secure hash, random number padding, and time stamp follow to meet the security requirements for WSN in Healthcare Applications: confidentiality, integrity, authorization, availability, and freshness. The scheme takes in consideration of WSN's resource constraints and mobility that hinder the applicability of conventional security schemes in WSN. Apart from general WSN-targeted security approaches that over-emphasize on energy consumption, this scheme provides robust, prompt, and scalable security services to healthcare systems.