On: “This telegram must be closely paraphrased before being communicated to anyone”

[hcs]

Compression + encryption can be dangerous if the compression rate is exposed somehow (between messages or within packets of a message).

> we show that it is possible to identify the phrases spoken within encrypted VoIP calls when the audio is encoded using variable bit rate codecs

https://crypto.stackexchange.com/a/2188

See also https://breachattack.com/ when the plaintext is partially attacker-controlled.