Sensors_**2010**, _10_, 1447-1472; doi:10.3390/s100301447  
_Article_  
**Achieving Network Level Privacy in Wireless Sensor Networks \({}^{\dagger}\)**  
**[PERSON] \({}^{1}\), [PERSON] \({}^{2,\ddagger}\), [PERSON] \({}^{1}\), [PERSON] \({}^{3}\), [PERSON] \({}^{1,\star}\)**  
**and [PERSON] \({}^{1}\)**  
\({}^{1}\) Department of Computer Engeering, Kyung Hee University, Global Campus, Korea;  
E-Mails: [EMAIL_ADDRESS] (R.A.S. ); [EMAIL_ADDRESS] (B.J.d'A. ); [EMAIL_ADDRESS] (Y.J.S.) \({}^{2}\) Computing Department, Macquarie University, NSW, Australia; E-Mail: [EMAIL_ADDRESS]  
\({}^{3}\) Department of Computer Science & Engeering, Korea University, Seoul, Korea;  
E-Mail: [EMAIL_ADDRESS]  
\({}^{\dagger}\) This paper is an extended version of our paper entitled \"Network level privacy for wireless sensor networks\" that has been published in proceedings of the 4\({}^{th}\) International Conference on Information Assurance and Security (IAS 08), that was held in Naples, Italy in September 2008 (pp. 261-266). \({}^{\ddagger}\) Contributed to this work when he was in Kyung Hee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul 130-701, Korea. \({}^{\star}\) Author to whom correspondence should be addressed; E-Mail: [EMAIL_ADDRESS]. _Received: 17 December 2009; in revised form: 4 February 2010 / Accepted: 9 February 2010 / Published: 26 February 2010_  
**Abstract:** Full network level privacy has often been categorized into four sub-categories: _Identity_, _Route_, _Location_ and _Data_ privacy. Achieving full network level privacy is a critical and challenging problem due to the constraints imposed by the sensor nodes (e.g., energy, memory and computation power), sensor networks (e.g., mobility and topology) and QoS issues (e.g., packet reach-ability and timeliness). In this paper, we proposed two new identity, route and location privacy algorithms and data privacy mechanism that addresses this problem. The proposed solutions provide additional trustworthiness and reliability at modest cost of memory and energy. Also, we proved that our proposed solutions provide protection against various privacy disclosure attacks, such as eavesdropping and hop-by-hop trace back attacks. **Keywords:** anonymity; eavesdropping; hop-by-hop trace back; privacy; routing; wireless sensor networksIntroduction  
With the spreading application of Wireless Sensor Networks (WSNs) in various sensitive areas such as health-care, military, habitat monitoring, _etc_, the need to ensure security and privacy is becoming imperatively important. For example, in battlefield application scenario, \"the location of a soldier should not be exposed if he initiates broadcast query\" [1]. In the meantime, query must be transferred to the destination in an encrypted manner via only trusted en-route nodes. Similarly, in habitat monitoring application scenarios, such as Great Duck Island [2] or Save-the-panda application [3] where large numbers of sensor nodes are deployed to observe the vast habitat of ducks and pandas, an adversary can try to capture the panda or duck by back-tracing the routing path until it reaches the source sensor nodes. Therefore, in order to prevent the adversary from back-tracing, the route, location and data privacy mechanisms must be enforced. With respect to these application scenarios, network level privacy has often been categorized into four categories:  
1. Sender node identity privacy: no intermediate node can get any information about who is sending the packets except the source, its immediate neighbors and the destination,
2. Sender node location privacy: no intermediate node can have any information about the location (in terms of physical distance or number of hops) about the sender node except the source, its immediate neighbors and the destination,
3. Route privacy: no node can predict the information about the complete path (from source to destination). Also, a mobile adversary gets no clue to trace back the source node either from the contents and/or directional information of the captured packet(s), and
4.