This is not part of the SSL standard, but is highly recommended to prevent a man in the middle attack (MITM).

虽然这不是SSL标准的一部分，但是这个步骤却是高度建议的，它可以防止中间人攻击。

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If the attacker sits in the middle of the network, then within the scope of the Internet, this attack becomes impractical.

如果攻击者在网络的中间，在Internet范围内，这种攻击是不可行的。

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They have someone who can tackle and who drops back when the full backs attack, adding balance in the middle of the park.

他们中有人铲抢精准，有人可以在大举压上时拖后、增加球队中场的攻守平衡。

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Also, client-side JavaScript encryption has its limitations since it would still be susceptible to a server-side code poisoning attack executed either through a man-in-the-middle attack or the service provider acting maliciously or subject to jurisdictional court order.

FORBES: Cryptocat Increases Security In Move Away From JavaScript Web Delivery

"Many of the systems we have built for authentication and session maintenance assume no man-in-the-middle attack, " he said.

BBC: Google tackled on e-mail security

The danger would have been that they could then have staged a man-in-the middle attack.

BBC: Google detects fake website ID certificate threat