Considering the characteristics of the entity authentication protocol, augment semantics SVO logic was used to describe its rationality and analyze its operation, and a flaw was found.

• 考虑该实体认证协议的特点，采用改进语义的SVO逻辑对其进行合理性描述，并对其运行过程进行形式化的具体分析，发现该协议在认证过程中存在着双方认证不确定的缺陷。