Sensor networks are expected to play an essential role in the upcoming age of pervasive computing. Due to their constraints in computation, memory, and power resources, their susceptibility to physical capture and use of wireless communications, security is a challenge in these networks. The scale of deployments of wireless sensor networks require careful decisions and trade-offs among various security measures Since there is an increase in possible software attacks on privacy and safety of health applications, safety and reliability of the sensor data is an important issue that needs to be addressed in this field. A unique design of a secure sensor node prototype has been proposed and implemented.