A paper-only journal would defend against the state, but not against people you live with. A digital journal can be encrypted, but an intelligence agency could potentially gain access (like, them reading your anti-government rants that may involve violence… that sort of stuff).
So… how to defend against both threats?
(Also, I just realized, paper journals cannot really be easily backed up…)
Digital with strong encryption, and protect the device so that it can’t be copied while unlocked. You’re probably not so important that they’d target you.
Security only works if you use it before you become a target.
Not actively, of course. I’m talking about when the authorities one day want to retroactively dig through stuff to find dirt.
The threat would be that they do a targeted attack on my devices and monitor for 72 hours, recording everything happening in my device, before they apprehend me.
(Not that the lack of evidence would stop them from trying, but the less info they get, the better chance I have)
If they’re on your device, you’ve already lost. To protect against that, you’d have to keep an offline device, either physical or digital. Digital encrypted, physical in a made-up language and script that only you know.