在大型而且密集的無線行動隨意網路 (MANET)，位置基礎的路由協定能夠提供良好的路由效能，它需要目的地的座標位置作為必要的路由資訊。位置資訊的使用能夠提升路由效能，然而它也是一個具有高度隱私的資料。因為無線網路訊號開放的特性，使得訊息內容非常容易被竊聽。為了保護私密資料，常見的方法是使用加密操作。資料加密會造成控制封包容量的增加以及處理時間的延遲，衝擊到路由效能。此外位置基礎的路由協定必須有一套完善的位置管理機制，它提供位置更新以及位置查詢的基本功能。為了在各個階段都能夠保持移動節點的匿名性以及保護它的位置隱私，我們提出一個具備安全性以及匿名性的位置服務機制，它的英文簡稱為SADLS。我們盡量減少加密操作的使用，而是透過使用假名的方式來隱匿隨意節點的真實識別名稱以及位置資訊這些私密資料。分析與模擬的結果顯示SADLS能夠得到比DISPOSER更好的安全性、匿名性以及效能。平均延遲時間在位置查詢時減少百分之五十八，在位置更新時減少百分之九十。

In large and dense mobile ad hoc network, location-based routing protocols which use location information of destination to make route decision can offer signif-icant route performance. It can promote route performance by using location infor-mation. However, it is also a high private data for person. Due to the characteristic of signal open in wireless network, it is very easy to eavesdrop the message contexts. To protect private data, encryption operation is a common method. Data encryption causes control packet size increase and operation latency, it impacts the network per-formance. Furthermore, location-based routing protocols must have a complete loca-tion service; it can offer the basic functions of location management, such as location update and location query. To maintain both anonymity of mobile node and protection of its location privacy at all stages, we propose a secure and anonymous distributed location service named SADLS. We reduce to use data encryption as much as possible. Thus, we hide the private data such as the real identity of mobile node and its location information through using pseudonym as identifier of node. Both analysis and simula-tion results show that SADLS can offer better security, anonymity and performance than DISPOSER. The average end-to-end delay for location query reduces 58%. However, it reduces 90% in location update.

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