第9套
_(1)__ is used to ensure the confidentiality,integrity and  authenticity of the two end points in the private etwork .the__(2) __,an application layer protocol,authenticates each peer in an IPsec  transaction ,IKE negotiates security policy,determining which  algorithm may be used to set up the Runnel .It also handles the exchang of session keys used for that  one transaction.Networks that use __(3)__to secure data traffic can  automatically authenticate devices by using __(4)__,which Verify the identities of the two users who are sending information  back and forth .IPsec can be ideal way to secure data in large  networks that require __(5)__ connections among many devices。 
(1) A.Encryption B.Code C.Certificate D. Tunnel 
(2) A.associated links B.Internet Key Exchange C IPsec D. encryption 
(3) A authenticity  B.password C.IPsec D. Internet Key Exchange 
(4) A.protocols  B.keywords C.IKE D. digital certificates 
(5) A.free B.strict C.secure D.remote 
答案:1:A,2:B,3:C,4:D,5:C