If you just mean locking chips and ship components so their contents can't be seen/edited without a password, I'd love to hear from the devs as well. I didn't find any posts from them about it after searching these forums, steam discussions, or reddit posts. That boltcracker video that showed someone can just run up and swap some values around was concerning.
If you mean encrypting the data YOLOL uses internally, i.e. for sending an encrypted message over transmitters and receivers, any encryption method would technically be possible given enough understanding and effort, but only if your input is already numeric, rather than text. After taking a look at the wiki page, it seems like YOLOL is too limited when it comes to strings to encrypt text. Maybe if there was an increment operation that edited the beginning of a string instead of the end, but there isn't one. You'd have to convert your string into numbers outside the game, at which point you might as well do it all outside the game and just PM each other through discord. The (slightly less than) 64bit limit means that asymmetric encryption would be a bit weak, anyway, so if frequency alone isn't enough privacy for you, then PMs outside the game are the better option regardless.