MPEG IPMP 之研究與實現

Abstract

智慧財產權 (IP) 的保護在今天是越來越重要。人們可以輕易地從網路上下載mp3音樂卻不用付任何錢，但這樣可能是違法的。有些人認為 “數位及網路革命” 已經造成了負面的影響而開始抗拒它。事實上，動態影像專家群 (MPEG, Moving Picture Expert Group) 已經發現IP的重要並且從MPEG-2就已開始IP保護的工作。數位電視的條件式接收 (CA, Conditional Access) 系統是一個很好的例子來證明MPEG-2 CA的成功。MPEG-4是最新的影音壓縮串流標準之一，它也具有IP保護的機制，他們稱呼它為IPMP (IP Management & Protection)。MPEG讓IPMP成為一個共通的名稱，只要是MPEG標準中所有有關IP保護的部分都可以這麼稱呼。IPMP自然也包括MPEG-2 CA。 本篇論文的目標在於模擬MPEG-4 Systems標準中有關IPMP的部分。除此之外，我們嘗試建立一個IPMP的應用，它是一個client-server的系統。在該系統中，用戶端可以像伺服器端要求多隻鑰匙，這些鑰匙會被加密傳送。我們利用階層式鑰匙的架構來管理鑰匙。我們利用密碼學中的技術來達到IPMP的要求。這篇論文包含四個部分。第一部份是MPEG-2以及數位電視CA的介紹，CA是IPMP系統的濫觴。第二部分是MPEG-4標準的概觀。我們特別專注在Object Descriptor及IPMP的部分。第三部份是分析IM1 Core及其IPMP API。最後一部份是建立一個利用IPMP的例子。這個例子展示了MPEG-4 Systems標準所提供的IP保護的功能。 IM1 Core的原始碼非常的冗長以及複雜。舉例來說2D player就有400個class及100,000行C++的程式。我們工作中很重要的部分是在追蹤這些原始碼並且了解其工作的原理。最後，我們建立一個IPMP plug-in，它是一個在Windows 2000中的動態連結資料庫 (dll)。它展示了MPEG-4 Systems中IP保護的功能。

Intellectual Property (IP) protection is getting more and more important nowadays. Presently, many Internet users misuse multimedia material without proper authentication. MPEG (Moving Picture Expert Group) started the IP protection project after MPEG-2 was nearly completed. The Conditional Access (CA) system of Digital TV is a good example that shows how a MPEG-2 CA can be implemented. MPEG-4 is one of the latest standards on streaming audio/video. And it has an IP protection mechanism, called IPMP (IP Management & Protection). IPMP is a generic name in MPEG. Every IP protection mechanism in MPEG standards bares the same name. The MPEG-2 CA is a part of MPEG IPMP. The goal of this thesis is to study and simulate the IPMP part of MPEG-4 Systems standard. In addition, we construct an IPMP application that includes a client-server program, in which a client can request the keys from a server in a secure way under the hierarchical key architecture. We use the cryptographic techniques to achieve the IPMP requirement. This thesis contains four parts. The first part is an introduction to MPEG-2 and DTV CA. This is the starting point of IPMP in MPEG. The second part is an overview of the MPEG-4 Systems standard. We especially concentrate on the Object Descriptor and IPMP. The third part is to analyze the IM1 Core and its IPMP API. The last part is to construct an IPMP application. This application demonstrates the protection of IP provided by MPEG-4 Systems standard. The source codes of IM1 Core are huge and complex. For example, the 2D player has about 400 classes coded in more than 100,000 lines in C++. A significant part of our work is tracing the codes (IM1) and knowing the behavior inside. Finally, we constructed an IPMP plug-in, which is a dynamic link library (dll) in Windows 2000. It demonstrates the IP protection using the MPEG-4 IPMP concept.