Why are you even asking here? Why not directly go to twitter or truth social? That seems the obvious choice based on all the red flags in your post.

You will have to do some work yourself (or hire someone to code the solution for you).

If the intended use is on linux, you could also write a bash script for it. If the position in the file (as in exact number of bytes till that position) is known, then you could use dd to cut the video file in two pieces, use gpg to encrypt the second part and then probably also use dd to put both pieces together again.

A video player like VLC should still be able to play the first part of the file (though other players might have bigger problems with such a file). To play the full file, you need to use your script to again seperate the two pieces, use gpg to decrypt the second part and put them back together.

You can also do this in python. Doing it cross platform (Linux, Mac and Windows) will be more difficult.

When renovating our house we bought new room doors. Though they took weeks to be delivered and we already lived in that house without room doors (also no door for the bathroom).

But we had loads of big cardboard pieces from furniture, so I used them and a lot of glue to build temporary doors. I added handles and used screws to fix them in the frame (I mean the big wooden beams, that are holding the actual nice doorframe in the wall).

They mostly worked surprisingly well, holding in the frame by friction from cardboard blocks, that I glued to them. Though they opened everytime, we had an open outside door, that caught some wind