為了避免遭受未知病毒的感染，許多藉由公正的編譯器製造者幫助的自動簽章方法已經被提出。在先前所提出的方法中，編譯器製造者與編譯器代理者之間的代理協議，需要用到兩份數位簽章，而同一件代理協議卻用到兩份數位簽章確認，是一件沒有效率的作法。為了改進此一沒有效率的缺失，提出第一個代理自動簽章法。又在先前所提出的方法與我們的第一個代理自動簽章法中，編譯器代理者們的公開金鑰必須被認證且驗證者必須被記錄下來，但如果只需要紀錄編譯器製造者的公開金鑰，那將會變的非常方便。因此一個匿名的代理自動簽章法被提出，在新的匿名方法中，編譯器的代理伺服器是匿名的，驗證者不需儲存代理伺服器的公開金鑰，並且驗證者可以事前偵測代理伺服器行為的逾越。我們所提出匿名的方法可以採用任何的離散對數型的簽章法，並且提供完善的裁判機制以偵測病毒感染的來源。

Many (proxy) automatic signature schemes are proposed to guard against the (unknown) virus infection with the help of honest compiler makers.  Among these proposed schemes, the agreement between the compiler maker and compiler severs is confirmed by two distinct signatures.  It is inefficient to adopt two distinct signatures to confirm the same agreement.  To overcome this inefficiency, our first scheme is proposed.  In these proposed schemes and our scheme, the used compiler agents’ public keys should be certificated and maintained by verifiers.  If verifiers only keep the compiler makers’ public key, it is more convenient.  So an anonymous proxy automatic signature scheme with compiler agents is proposed.  In the new scheme, the compiler agents are anonymous and verifiers do not need to store compiler agents’ public key.  Moreover, verifiers can authenticate the source of received executable problems and detect compiler agents’ deviation in advance.  Our schemes are suitable for adopting any discrete logarithm based signature schemes.  Our scheme has provides strong moderator’s judgment to detect of virus infection sources.

Chapter 1	 Introduction P.1
1.1 Motive P.1
1.2 Basic Assumptions and Models P.3
1.3 Security Goals in Our schemes P.6
Chapter 2	 Review of Past Results P.9
2.1 Review of Hwang and Li’s scheme	P.9
2.2 Review of Hwang and Chan’s scheme P.14
Chapter 3	 A Proxy Automatic Signature scheme Using a Compiler in Distributed Systems for (Unknown) Virus Detection	 P. 19
3.1 Our Realization of Proxy Automatic Signature scheme Using a Compiler in Distributed Systems for (Unknown) Virus Detection P.19
3.2 Security Analysis of Proxy Automatic Signature scheme Using a Compiler in Distributed Systems for (Unknown) Virus Detection P.24
Chapter 4　Our Realization of Anonymous Proxy Automatic Signature schemes with Compiler Agents P.26
Chapter 5　Security Analysis of Anonymous Proxy Automatic Signature schemes with Compiler Agents P.32
Chapter 6	 Performance Analysis and Discussion	P.35
Chapter 7	 Comparison P.40
Chapter 8	 Conclusion P.42
References P.43 

List of Tables
Fig 1 Client-Server Model in Distributed Systems P.6
Fig 2 Computational Cost in Compiler-Maker Authorization Phase P.36
Fig 3 Computational Cost in Server-Requester Execution Phase P.37
Fig 4 Computational Cost in Customer Verification Phase  P.38
Table 1 Computational Cost of Participates in Our Second scheme P.39
Table 2 Comparison among Four Automatic Signature schemes  P.41

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