在無線感測網路中，安全性定位法是一個很重要的議題。近年來随著移動式無線感測網路的蓬勃發展，如何在移動式無線感測網路中定位也逐漸獲得重視。然而這類大部分定位的研究都是假設在安全的環境下，但是在現實中應用，無線感測器有很大的機率會被佈建在危險的環境中，導致定位誤差擴大。例如：因為大多數的定位法都需要感測器間的訊息交換，如果其中有惡意的感測器故意發佈錯誤的資訊，可能會導致定位結果不準確。但是大部分關於安全式的定位法都是假設在靜態的感測網路下，在移動式網路中的安全定位相對來說較少。因此在這篇論文中，我們對目前很有名的蒙特卡羅定位法提出一個安全的策略，利用我們提出的方法，我們有盡可能的抓出潛在的攻擊者並刪除這些錯誤的位置資訊。在我們的模擬中，結果顯示在我們的方法下，攻擊者被偵測出來的機率很高而且在危險環境中的定位誤差也很接近在安全環境中的定位誤差。

The security of localization is an important issue in wireless sensor networks. Recently with rapidly development of wireless mobile sensor networks, localization in wireless mobile sensor networks has attracted much attention, and many localization algorithms have been proposed for this research area. However, most of them are assumed in secure environments. In fact, sensors are most likely to be deployed in hostile environments, and malicious nodes perform harmful behaviors to interfere with the localization process, for example, malicious nodes (attackers) send wrong location information to normal nodes so as to disrupt the localization process. Therefore, the behaviors of malicious nodes may lead to estimate locations incorrect and inaccurate. However, most localization research for security focuses on static sensor networks. Few of them consider about the security of localization in mobile sensor networks. In this paper, we propose a secure strategy to improve the security of Monte Carlo Localization (MCL) algorithm. Moreover, with the secure MCL, the attackers can be detected as many as possible, and the location messages sent by attackers will be discarded. Simulation results show that the ratio of detecting attackers in our proposed algorithm is high, and the average localization error is closed to the secure environments.

[1] A. Baggio and K. Langendoen, “Monte-Carlo Localization for Mobile Wireless Sensor Networks,” in Proceedings of Second International Conference on Mobile Ad-Hoc and Sensor Networks, pp. 317-328, December 2006.
[2] J. Broch, D.A. Maltz, D.B. Johnson, Y.-C. Hu, and J. Jetcheva, “A Performance Comparison of Multi-Hop Wireless Ad Hoc Network Routing Protocols,” in Proceedings of The Annual International Conference on Mobile Computing and Networking (MobiCom), pp. 85-97, October 1998.
[3] N. Bulusu, J. Heidemann, and D. Estrin, “GPS-Less Low Cost Outdoor Localization for Very Small Devices,” IEEE Personal Communication Magazine, Vol. 7, No. 5, pp. 28-34, October 2000.
[4] S. Capkun and J.-P. Hubaux, “Secure Positioning of Wireless Devices With Application to Sensor Networks,” in Proceedings of IEEE International Conference on Computer Communications (INFOCOM), Vol. 3, pp. 1917-1928, March 2005.
[5] S. Capkun, M. Cagalj, M. Srivastava, “Securing Localization With Hidden and Mobile Base Stations,” IEEE Transactions on Mobile Computing, Vol. 7, No. 4, pp. 470-483, April 2008.
[6] L. Doherty, K.S.J. Pister, and L. El Ghaoui, “Convex Position Estimation in Wireless Sensor Networks,” in Proceedings of IEEE International Conference on Computer Communications (INFOCOM), Vol. 3, pp. 1655-1663, April 2001.
[7] T. He, C. Huang, B.M. Blum, J.A. Stankovic, and T.F. Abdelzaher, “Range-Free Localization Schemes in Large Scale Sensor Networks,” in Proceedings of The Annual International Conference on Mobile Computing and Networking (MobiCom), pp. 81-95, Sept. 2003.
[8] L. Hu and D. Evans, “Localization for Mobile Sensor networks,” in Proceedings of The Annual International Conference on Mobile Computing and Networking (MobiCom), pp. 45-47, September 2004.
[9] M. Ilyas and I. Mahgoub, Eds., “Handbook of Sensor Networks: Compact Wireless and Wired Sensing Systems,” CRC Press LLC, 2005.
[10] L. Lazos, S. Capkun, and R. Poovendran. “ROPE: Robust Position Estimation in Wireless Sensor Networks,” in Proceedings of International Conference on Information Processing in Sensor Networks (IPSN), pp. 324-331, April 2005.
[11] L. Lazos and R. Poovendran. “SeRLoc: Robust Localization for Wireless Sensor Networks,” ACM Transactions on Sensor Networks, Vol. 1, No. 1, pp. 73-100, August 2005.
[12] L. Lazos and R. Poovendran. “HiRLoc: High-Resolution Robust Localization for Wireless Sensor Networks,” IEEE Journal on Selected Areas in Communications, Vol. 24, No. 2, February 2006.
[13] Z. Li, W. Trappe, Y. Zhang, and B. Nath. “Robust Statistical Methods for Securing Wireless Localization in Sensor Networks,” in Proceedings of International Conference on Information Processing in Sensor Networks (IPSN), pp. 91-98, April 2005.
[14] C. Liu, K. Wu, and T. He, “Sensor Localization with Ring Overlapping Based on Comparison of Received Signal Strength Indicator,” in Proceedings of IEEE International Conference on Mobile Ad-Hoc and Sensor Systems (MASS), pp. 516-518, Oct. 2004.
[15] D. Liu, P. Ning, and W. Du, “Attack-Resistant Location Estimation in Sensor Networks,” in Proceedings of the International Conference on Information Processing in Sensor Networks (IPSN), pp. 99-106, April 2005.
[16] D. Niculescu and B. Nath, “Ad-hoc positioning system,” in Proceedings of Global Telecommunications Conference (GlobeCom), November 2001.
[17] R. Peng and M.L. Sichitiu, “Robust, Probabilistic, Constraint-Based Localization for Wireless Sensor Networks,” in Proceedings of IEEE Communications Society Conference on Sensor and Ad Hoc Communications and Networks (SECON), pp. 541-550, September 2005.
[18] J.-P. Sheu, J.-M. Li, and C.-S. Hsu, “A Distributed Location Estimating Algorithm for Wireless Sensor Networks,” in Proceedings of IEEE International Conference on Sensor Networks, Ubiquitous, and Trustworthy Computing, Vol. 1, pp. 218-225, June 2006.
[19] J.-P. Sheu, P.-C Chen, and C.-S. Hsu, “A Distributed Localization Scheme for Wireless Sensor Networks with Improved Grid-Scan and Vector-Based Refinement,” IEEE Transactions on Mobile Computing, Vol. 7, No. 9, pp. 1110-1123, September 2008.
[20] J.-P. Sheu, W.-K. Hu, and J.-C Lin, “Distributed Localization Scheme for Mobile Sensor Networks,” IEEE Transactions on Mobile Computing, Vol. 9, No. 4, April 2010.
[21] A. Srinivasan, J. Teitelbaum, J. Wu, “DRBTS: Distributed Reputation-based Beacon Trust System,” in Proceedings of IEEE International Symposium on Dependable, Autonomic and Secure Computing (DASC), pp. 277-283, 2006.
[22] R. Stoleru, T. He, and A. Stankovic, “Range-Free Localization,” Secure Localization and Time Synchronization for Wireless Sensor and Ad Hoc Networks, Vol. 30, Springer, 2007.
[23] F. Zhao and L. J. Guibas, “Wireless Sensor Network: An Information Processing Approach,” Morgan Kaufmann Publishers, 2004.