True, but you could compress then encrypt. There have been what’s called “compression oracle” attacks on SSL with compress then encrypt scheme, see CRIME htt

True, but you could compress then encrypt. There have been what’s called “compression oracle” attacks on SSL with compress then encrypt scheme, see CRIME https://en.m.wikipedia.org/wiki/Oracle_attack https://en.m.wikipedia.org/wiki/Oracle_attack An attacker could inject known plaintext to an unknown source and observe the size of the ciphertext. If the size doesn’t change much, it means the chosen plaintext is correlated with the source. Several variants exist. Compression is often not recommended in VPNs.