(66) is used to ensure the confidentiality, integrity and authenticity of the two end points in the private network. (67) , 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 tunnel. It also handles the exchange of session keys used for that one transaction.
Networks that use (68) to secure data traffic can automatically authenticate devices by using (69) , 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 secure connections among many devices.
Users deploying IPsec can (70) their network infrastructure without affecting the applications on individual computer. The protocol suite is available as a software-only upgrade to the network infrastructure. This alows security to be implemented without costly changes to each computer. Most important, IPsec allows interoperability among different network devices, PCs and other computing systems.

A．secure

B．relation

C．script

D．strict

有关货物装卸的一般原则描述正确的是（）。

A.在装卸贵重货物、重大件货物及危险货物时，当班驾驶员应亲临现场指挥

B.港方要求调整配积载计划，船方应予拒绝

C.装卸件杂货，可申请理货部门理货，但船方不能放弃对理货部门的监督之责