Date Added: Jul 2010
Group communication has proven to be a powerful paradigm for designing applications and services in Wireless Sensor Networks (WSNs). Given the tight interaction between WSNs and the physical world, a security infringement may translate into a safety infringement. Therefore, in order to fully exploit the group communication paradigm the authors need to secure it. Traditionally, this requirement has been formalized in terms of backward and forward security and fulfilled by means of rekeying. In WSNs, group rekeying becomes particularly a complex problem because communication takes place over an easily-accessible wireless medium and because sensor nodes have severe limitations in terms of computing, storage, energy and tamper-resistance capabilities for cost reasons.