【判断题】密码学的两大分支是密码编码学和密码分析学。( )
【单选题】The ditry tricks played upon the Secretary of the State are ______ by the high ranking officials behind the scenes.
【单选题】When the woman told Smith that the gray-haired man at the end of the table was the Secretary of the International Department, Smith _________.
A.
said something against the Secretary
B.
said something nice about the Secretary
C.
was very pleased to hear that
D.
wanted to make friends with the Secretary
【单选题】关于密码学的讨论中,下列()观点是不正确的。
A.
密码学是研究与信息安全相关的方面如机密性、完整性、实体鉴别、抗否认等的综
C.
密码并不是提供安全的单一的手段,而是一组技术
D.
密码学中存在一次一密的密码体制,它是绝对安全的