許多無線感測器網路中的應用程式需要精準的對時，所以如何針對無線感測器網路中的時間同步協定來做安全性的考量是此篇論文所討論的重點。現今無線感測器網路中已開發的時間同步協定大多是純粹為了支援動態或是要求更精準的時間而設計，所以在設計的最初就沒有把安全性加入考量，所以相當容易遭受到攻擊。然而，雖然在感測器網路中，可以使用金鑰系統來解決某部份網路封包傳送時的安全性議題，但是由於考慮到動態網路環境以及無線感測器網路中金鑰系統的強度，我們希望能夠另外的使用過濾方法來加強封包的處理，以期使在金鑰系統被破解之後，還能夠有另一層的防護，所以此篇論文不討論金鑰的部份。
我們先就目前在無線感測器網路中時間同步精準度較高且支援動態網路環境的氾濫式時間同步協定做分析，並研究其協定如何溝通後，再提出可能的弱點有哪些，進而在協定上進行攻擊的實作，最後使用所提出的過濾器來對錯誤的網路封包進行篩選，以達防禦的效果。我們所使用的方法不會破壞協定的時間精準性，且依然能夠保持在動態的網路環境中發揮功效。透過實驗，我們可以清楚地看到，最後提出的演算法能夠確保在一定數量的惡意節點中，過濾其錯誤的網路封包，達到防禦的效果。

Many applications in wireless sensor networks need precise and unitary time; therefore, how to secure time synchronization protocol is an important issue. Without key management problems, we tired to filter out incorrect data if there were compromised nodes. And then we use a new algorithm to complete this method. In this paper, some attacks and defenses have been implemented. In order to make sure that all the participated nodes can be calibrated to the same time, some of time synchronization protocols have been proposed. However, no one of them has been created with security concern. Therefore, adversary can crash the time synchronization protocol easily. On account of sensor nodes may be severely resource constrained, the traditional time synchronization and securing methods could not be applied on sensor networks. Moreover, FTSP is especially excellent and the latest protocol among them. Hence, the proposal we proposed is designed exactly for FTSP.

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