We started taking precautions. We started passing codes.

我们便采取了防备措施 采用密码通信。

Both Anthony Blunt and John  Cairncross worked at Bletchley Park, where daily secret communications  and code-breaking were conducted.

安东尼·布朗特 (Anthony Blunt) 和约翰·凯恩克罗斯 (John Cairncross) 都曾在布莱切利公园工，那里每天进行秘密通信和破译密码。

A few centuries later, in World War II, the Nazis communicated using the Engima code, a much more complicated encryption scheme that they thought was unbreakable.

纪后， 在第二次界大战中， 纳粹使用 Engima 密码进行通信，这是一种他们认为牢不可破的更为复杂的加密方案。