Institute of Fundamental Technological Research

Broadcasting is a message-transferring method characteristic for majority of sensor networks. Broadcast encryption (BE) is broadcasting encrypted messages in such a way that only legitimate nodes of a network can decrypt them. It has many potential applications in distributed wireless sensor networks (WSNs) but perfect deploying of that method is very difficult. This is because of a WSN is a very dynamic network which includes nodes with limited computational, storage, and communication capabilities. Furthermore, an attacker in this environment is powerful. He can eavesdrop, modify, and inject messages or even capture a large number of nodes, so the solutions must be both secure and efficient. This paper describes several BE schemes from the point of view of WSNs. We present in details the schemes called onetime, and we show how these methods can be applied in distributed sensor networks. We mainly focus on data origin authentication and rekeying processes, crucial for security in such a hostile environment. An analysis and evaluations of proposed schemes are also provided.

Symmetric block ciphers are usually used in WSN for security services. This paper puts forward the idea of using advanced modes of operation of symmetric block ciphers to achieve confidentiality and authentication in one cryptographic operation. The modes of operation approved by NIST that is CMAC, CCM, GCM/GMAC are applied here. The benchmarks of these approaches in the terms of efficiency of nodes in WSN are presented.

Wireless sensor network, Cryptographic protocols, Block cipher modes, Sensor's security, Utilization efficiency

Cryptographic protocols are secure due to application of security services. The security services applied for their protection can be classified into the three groups: hard, soft and extended. Among the extended ones, we can point out to the availability of the goal of the security protocol, which guarantees that protocols aims are achieved. In the real-time protocols as the video conference, the goal is both secure data transmission and good signal quality. When one of the goals is not ensured, the availability of the goal of the protocol is not guaranteed and the cryptographic protocol can not be realized. In this article we present the methodology of obtaining the balance between the quality of the signal in real-time systems and accomplishment of the required security services. Finally, the case study of video conference secured by VPN connections, is presented.