有效減少通訊回合數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，可能會有被竊聽的危險，因此在召開會議之前，所有的會議參與者應該要先建立起一個共同的會議金鑰，以用來加密通訊的內容。 而在建立會議金鑰的過程之中，可能會有部分的惡意參與者蓄意不遵照會議金鑰的建立流程，使得正確的參與者不能得到共同的會議金鑰值，所以如何讓合法的使用者建立同樣的會議金鑰值，就是一個重要的問題。 在正確的建立會議金鑰的同時，整個會議金鑰系統的效率問題也是我們應該要考慮的。因此在本篇中，提出三個可以讓合法參與者正確的建立會議金鑰的協定，這些協定的回合數可以被有效的降低。

When some members want to hold a conference via an open Internet, there may have passive attackers eavesdropping the communication. Therefore, all participants should establish a common conference key to encrypt the entire communication session during the conference. Futhermore, when the participants execute the conference key agreement protocol, some malicious participants may not follow the protocol and try to cheat the honest participants to compute the different conference keys. So how to make sure that the honest participants get a common conference key is one of the major concerns. Besides these, the efficiency of the protocol is also very important. Thus, we proposed three round-efficient conference agreement protocols. No matter how many malicious participants there are, the honest participants will get a common conference key.