本文给出一类新的完善保密协议———优先退化协议 ,它与以往的优先提取协议具有不同的功能 :优先提取是指通信伙伴的互信息被首先提取 ,而优先退化是指敌方掌握的信息被首先退化 .本文讨论了优先退化协议有效的条件 ,并给出了一个同时具有优先提取和优先退化功能的混合协议 In this paper, we give a new class of imperfect agreement, Priority Degradation Protocol, which has different functions from the prior one. The first extraction is that the mutual information of the communication partner is first extracted, while the first degradation is the enemy’s control The information is degraded first.This paper discusses the conditions for the degenerate protocol to be valid and presents a hybrid protocol that has both prioritized and degenerate functions