Most secure Operating System

If your adversary does not see your device as an interesting target he will not pwn it, that's half of the point of opsec.
The other half is being able to say "you can't prove anything", but it's best not to reach that point.

If you tune your fingerprint to a browser that doesn't support a certain compression algorithm but your browser still sends requests to use that algo, this creates a whole new unique identity that opens up to some OPSEC nightmare. Better use Tor Browser and call it a day.

This information was originally posted by another user but I'm posting it again in case you didn't see it.

the one on a computer with no internet connection

It would be great if Qubes moved to or started supporting sel4 builds. The one thing Xen does have going for it is that it's used heavily by a lot of big names, so there's a vested interest in its continued development and security.

temple os

Correct, although seL4 is ideal iirc Qubes team went with Xen for its greater support for hardware and the like. There've been discussions years back about this very topic, but in the end they went with greater compatibility.

groups.google.com/forum/#!msg/qubes-users/tz_945JPpJ8/6g0orvWyG9UJ

Though really, most OS' are secure enough provided you're not an idiot installing things from ads. These security threads get pretty autistic honestly. You're shitposting on an imageboard, not managing trillions in financial flows. If you want the most secure system out there, find out what Fedwire or SWIFT run on, probably something proprietary with a team of highly-paid devs on it 24/7.

Perfect security doesnt exist thou
youtube.com/watch?v=C1EJvDU2Ek4

TempleOS has never had a security breach as far as i know

Probably some mainframe OS thing like AS400, system Z, etc. Quite secure by virtue of the fact most of the millenial skiddies won't have the slightest fucking clue how to operate it, and learning to do so is nontrivial.

I have a friend that works for a major US bank and they use an IBM mainframe z/OS. He had to learn jcl to work with it. What a language.