雖然指定驗證者簽章提供了簽章者的模糊性，卻沒有提供任何一個當指定驗證者簽章被確定是合法後，保護指定驗證者身分隱私的方法。為了要保護指定驗證者的身分隱私，提出了一個具有驗證者模糊性的指定驗證者模糊性的指定驗證者簽章法。一旦一個指定驗證者簽章被確認是合法的之後，指定驗證者的身分仍然是受到驗證者模糊性所保護。另外，我們的方法中還提供了可澄清的機制使得簽名者得以澄清簽名者的清白。

Though the designated verifier signatures provide signer ambiguity, there is no identity privacy protection for the designated verifier who has believed true designated verifier signatures.  To protect the designated verifier’s identity privacy, an ambiguously designated verifier signature scheme with one-out-of-many verifier ambiguity is proposed.  Even though the designated signatures are believed to be true, the designated verifier is still hidden by one-out-of-many verifier ambiguity.  Moreover, in our scheme, a disavowability mechanism is proposed to help the real signer to clarify his/her innocence.

Chapter 1 Introduction	1
Chapter 2 An Ambiguously Designated Verifier Signature Scheme	5
2.1 Assumption	5
2.2 An Ambiguously Designated Verifier Signature Scheme	6
Chapter 3 Security Analysis	9
Chapter 4 Conclusions	19
References	20
Appendix A	25

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