Optimizing time schedule of key updates in ISA100.11a

Wireless Industrial Sensor Networks (WISN) has many challenges like low-resources, harsh environmental conditions, QoS, integration with other wireless technologies and security. In particular, security is the most important to protect the information of critical infrastructure. ISA100.11a is an industrial standard of WISN, includes key update protocol in its standard in order to protect key exposal. In this paper, we analyze the key update problems of ISA100.11a and investigate the way of calculating optimal key update interval for efficiency. Finally we suggest the algorithm that is for organizing time schedule of key updates using calculated interval and evaluate the performance of proposed algorithm by simulations.