Imagine having to crack open a codebook to connect to youtube!

想象一下必须破解密码本才能连接到 youtube！

In the old days, keys would be shared by voice, or physically; for example, the Germans distributed codebooks with daily settings for their Enigma machines.

在过去，密钥会通过语音或物理方式共享；例如，德国人为他们的 Enigma 机器分发了带有日常设置的密码本。