Consideration of Security in Tele health Wireless Sensor Network Monitoring Systems
Jocelyn Adams, Tanya G. Roosta, Johan Eklund, Ruzena K. Bajcsy, Shankar Sastry · 2007
Wireless sensor networks provide the potential to provide effective and cost efficient remote and/or ubiquitous health care monitoring as they are easy to install, robust and secure. However, by their nature, these WSNs use asynchronous communica-tions to reduce transmission power and improve efficiency, however this create potential issues with the synchronization of the data received and stored by the telehealth system that this could be part of, particularly if multiple sensors are employed, which is very likely due the nature and relatively low cost of such devices. Time synchronization is one essential component to maintain the security of such a system and for data transmission through wireless sensor networks (WSN). Each individual node in a WSN contains a crystal clock. Although the natural frequency of each crystal clock remains relatively constant, the quality of the crystal and environmental factors such as temperature cause the frequency to drift over time. In order to ensure that each node broadcasts the same global time within the micro-second range a time synchronization protocol must be implemented. Several protocols have been developed however none has been developed with security in mind. It is easy for a system error or even a malicious third party to compromise a node causing faulty time sync messages to be sent out into the network. The Flooding Time Synchronization Protocol (FTSP) is the proposed protocol to ensure time sychrony in the proposed telehealh WSN. The FTSP is made up of several component modules written in nesC and is implemented in the TinyOS