It’s a telegram in cipher.

这是密码电报。

Only the capture of an Enigma machine and the invention of radar could spur a fightback.

及后盟军解德军电报机密码，并发明雷反击，才有所转机。

She had been posing as a diplomat, but her cover was blown when she was found sending coded messages to agents.

她表面的身是外交官，可是被发现给特务发送密码电报，暴露了真实身。