Global Time Synchronization Sample Clauses

Global Time Synchronization. Due to the collaborative nature of sensor nodes over WSNs, many applications require global time synchronization. Several time synchronization algorithms have been proposed for WSNs [14-17]. However, many of the schemes were not designed with security in mind. Xxxx et al. provided vulnerabilities in most existing time synchronization schemes as follows [18] Masquerade attack: Suppose that a node A sends a reference beacon to its two neighboring nodes B and C. An attacker E can pretend to be B and exchange wrong time information with node C, disrupting the time synchronization process between nodes B and C. Replay attack: Using the same scenario in the masquerade attack, attacker E can replay node B’s old timing packets, misleading node C to be synchronized to a wrong time. Message manipulation attack: In this attack, an attacker may drop, modify, or even forge the exchanged timing messages to interrupt the time synchronization process. Delay attack: The attacker deliberately delays some of the time messages, e.g., the beacon message in the reference broadcast synchronization scheme in [14], to fail the time synchronization process. Note that this attack cannot be defended by cryptographic techniques. Thereby, it is not easy to establish a synchronized time over a WSN and thereby, it is better to not use timestamp based technique in the security schemes. However, the freshness of the message in Juang et al.’s scheme is based on the timestamp, TSi.

Global Time Synchronization. The proposed scheme is based on the challenge-response mechanism, which does not use time stamp to provide session freshness. The proposed scheme uses session fresh random numbers Ki and Kj. There is no way an attacker knows them due to the difficulty of the discrete logarithm problems of PUi and PUj. Therefore, the proposed scheme is very good to be deployed at WSNs.