自適性串流的目的是客戶端透過目前使用的網路狀況動態調整從伺服器端存取的節目品質，讓使用者有更好的使用體驗，所以此技術日益被應用在網路多媒體服務上，而由於網際網路的使用環境是公開的，傳送的封包會有被攔截竊聽的疑慮，對內容提供商來說，多媒體內容在網路傳送時的保護，是很重要的議題。本文將介紹自適性串流技術中最新提出於標準組織IETF討論中的HTTP Live Streaming第八版本草案，其中對於內容的保護方式，並在介紹基本的網路安全加解密方式後，也對自適性串流的內容保護方式進行討論與實作介紹，讓負責傳送資料的伺服器在傳送過程中不需增加伺服器與客戶端太多額外的運算量，同時能確保傳送資料的安全性。

The purpose of adaptive streaming is the client can choose the proper multimedia content from the server based on the condition of bandwidth it can deliver to achieve a better Quality-of-Experience. Therefore, there are more and more Internet video service providers adopt this kind of technology to deploy their services. Due to the open environment of Internet, the transmission packets will be eavesdropped and this is a serious issue for content provider to have their content transmitted securely on Internet. This paper will introduce the latest IETF draft of HTTP Live Streaming version 8 and the content protection mechanism for dynamic adaptive streaming. We will also give the background knowledge of network security and explains the implementation of our protection mechanism for adaptive streaming. Our architecture can make sure the security of multimedia content without costing too much computing effort of server and client.