一個安全群播上的樹狀結構金鑰管理協定

Abstract

金鑰管理系統是應用程式要達到安全的一個選擇。由於網路的發達，現今有越來越多人需要使用網際網路(internet)來當作生活中的一部份。當使用者與資料量日漸增加，使用一對一來傳送資料已經變成毫無效率可言。群播(multicast)便是一個很好的技術, 用它來達成有效率的資料傳送, 是電腦網路上的一大突破。 對於安全群播的研究是近幾年才開始為人所注意，從最原始的毫無結構發展到階層式架構或樹狀結構，可顯示出前人的用心與努力。但這些方法均有其限制與缺點，我們想要去蕪存菁，藉此來達到更安全且更有效率的群播系統。 在這篇論文中，我們針對群播，提出一套有效率且安全的金鑰管理協定。此協定是利用樹狀結構來有組織的排列著少量的輔助金鑰，因而達成動態且安全的目地。最後在效率方面，我們使用少量的金鑰，也能達到與前人幾乎一樣的效果，是本篇論文的一大特色。

The system of key management is a way for an application to security. As a result of the development of computer networks, more and more people use internet as a part of their daily life. When the number of users and messages multiply day after day, one-to-one transmission turns inefficient. As a result, multicast brings in a new era on the computer network: it appears a good technique which helps achieve the goal of efficient communication. Secure multicast has not been paid much attention until recent years. We can perceive our predecessors’ efforts from the improvement from the original situation of no structure to a tree structure or a hierarchical structure. Since these approaches result in both advantages and disadvantages, we intend to preserve advantages and to get rid of disadvantages to produce a securer and more efficient multicast system. As to multicast, we propose an efficient and secure protocol of key management in this thesis. It achieves the goal of scalability and security by placing a few auxiliary keys in the tree structure. Finally, the characteristics of the protocol is that we use fewer keys to operate nearly as efficiently as scholars before.