多项选择题
Which classes does the U.S. government place classified data into？ （）
A.Top-secret B.Confidential C.SBU D.Secret
单项选择题 Whichisthemaindifferencebetweenhost-basedandnetwork-basedintrusionprevention？（）
单项选择题 Whichalgorithmwasthefirsttobefoundsuitableforbothdigitalsigningandencryption？（）
单项选择题 Whichexampleisofafunctionintendedforcryptographichashing？（）
