JWCN_V3_N3_RP2 Dhana Bhavithra Anandamurugan S. Journal On Wireless Communication Networks 2320 - 2351 3 3 12 17 SOBAS (Source-BAsed loose Synchronization), Loose Synchronization, Wireless Sensor Network, Dynamic Enroute Filtering The Secure Source-BAsed loose Synchronization (SOBAS) protocol is introduced, to securely synchronize the events in the network, without the transmission of explicit synchronization control messages. Nodes use their local time value and initial vector value as a one-time dynamic key to encrypt each message. SOBAS provides an effective dynamic en-route filtering mechanism, where the malicious data is filtered from the network. Instead of synchronizing each sensor globally, SOBAS focuses on ensuring that each source node is synchronized with the sink such that event reports generated by the sink are ordered properly. Hence, the objective of the SOBAS protocol is to provide a loose synchronization protocol for WSNs rather than a perfect synchronization among the nodes. With loose synchronization, it reduces the number of control messages needed for a WSN to operate providing the key benefits of reduced energy consumption as well as reducing the opportunity for malicious nodes to eavesdrop, intercept, or be made aware of the presence of the network. Thus, SOBAS (Source-BAsed loose Synchronization) provides energy efficient and an effective technique to securely synchronize the nodes on the data delivery path in the network. October - December 2014 Copyright © 2014 i-manager publications. All rights reserved. i-manager Publications http://www.imanagerpublications.com/Article.aspx?ArticleId=3080