| Summary: | 碩士 === 國立中央大學 === 資訊管理研究所 === 81 === @ 網路技術不斷創新，促使未來電信網路將轉為數據通訊，提供多樣化
的多媒體資訊服務，而現存之電腦網路將隨需求不斷擴張，與電信網路整
合成一數位網路。致使網路範圍擴大、使用者增多、資訊服務品質的需求
也隨之提升，使得現存之安全遠端程式呼叫(SRPC)在安全性與效率方面皆
面臨嚴厲的挑戰。 本論文之主要成果是首先提出一嶄新之物件活動
圖(OAD)表示方式，作為設計分散式系統軟體之輔助工具，來實際輔助
SRPC之設計；透過物件間相互活動關係之分析，減少軟體模組之不良切割
。接著；發展一新SRPC的架構，避免使用 Name Server與
Authentication Server，提出新SRPC之設計，證明其通訊協定功能之正
確性，以改進世界上現存之SRPC，使得其不但能滿足未來網路上安全性之
需求，並改善其執行效率，增進其執行方便。另分析比較現今世界上存在
之五種SRPC：Amoeba、Andrew、Courier、Kerberos、Sun與新設計之SRPC
，證實新設計之SRPC較現存者為佳，不僅使用之通訊協定較為簡單，且不
依賴Timestamp，使得加密後的訊息較難以被侵入者解開，且不必考慮
Client與Server時間同步的問題。 因為現存SRPC皆使用DES作為加密
系統，進而對DES的架構、內部詳細之設計、運作方式、特性加以深入探
討，並整理、分析、比較與改進解DES key之方法，以便找出DES在安全上
需補救之弱點。
As the data communication networks being innovated ,
telecommunication networks will be spurred to be digitized for
supporting various multimedia information services in the
future, and the computer networks will also be expanded and
integrated with data communication networks in demand.
Therefore, networks are spanned, number of users are increased,
and the qualities of information services are getting better.
Both in security and efficiency, the current SRPCs (Secure
RPCs) are in face of critical defy. In this paper, a new
representation style for assisting modeling the design of
distributed system software, called OAD (Object-Activity
Diagram), is proposed to really assist the design of SRPC, and
to minimize ill decomposition of software by analyzing the
activity relationships between objects. Also a new SRPC
architecture is developed without using name server and
authentication server. To improve current SRPC, the new design
of SRPC is proposed, and the correctness of its protocol
functions are also proved. Therefore, the future network
security demands are satisfied, and both the efficiency and
convenience of execution are also enhanced. In addition, the
five current SRPCs: Amoeba, Andrew, Courier, Kerberos, and Sun,
and the new SRPC design are analyzed and compared, sustaining
the advantages of the new design such as simplified protocols
and minimized use of encrypted timestamps. Since DES (Data
Encryption Standard) has been used in current SRPCs, the
structure, detail design, operations, and characteristics of
DES are discussed. The methods of breaking DES keys are also
codified, analyzed, compared, and improved to find out the
security weakness of DES.
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