具容錯性質的分散式會議金鑰系統

Abstract

當一群人想要在開放式的網路上召開一個會議時，可能會遭受到竊聽的危險，所以會議的參與者應該要在傳遞會議通訊內容之前，先建立起一個共同的會議金鑰，再用此會議金鑰加密所有的通訊內容。 然而在建立會議金鑰的過程中，可能有部份的參與者惡意地欺騙其他的參與者，使得正確的參與者不能得到共同的會議金鑰值。 在本篇中，提出一個在沒有可信賴中心存在的分散式環境下，由所有參與者共同建立一會議金鑰的協定。且在惡意的參與者少於一半的情況下，所有正確的參與者可以建立起唯一的會議金鑰值。同時以零知識證明的方式證明此協定對於在一旁竊聽的旁觀者而言，將不會洩露出任何的資訊。

When some members want to hold a conference over the open Internet, maybe there are some passive attackers trying to eavesdrop the communication. So those conference participants should establish a common conference key before the conference, and then they could use the conference key to encrypt the communication messages during the conference. But when those conference participants are executing a conference key agreement protocol, some malicious participants would try to cheat other participants, and let the honest participants fail to get a common conference key. We proposed a distributed conference key agreement protocol without any trusted authentication center. If the majority of participants are honest, the honest participants will establish a common conference key. Our protocol is zero-knowledge against a passive attacker.