Can you trust anyone? How much trust do they need to have. If you actually want to be secure. Don’t use any encryption provided inside a program. Even if code is supposedly open source. If you didn’t audit the code before compiling it yourself. It may as well still be a black box. If tight security is a must. Then nothing beats negotiating one time pads with those you are going to interact with. They’re one of the few things that are actually uncrackable unless someone gets a hold of your pad. Write whatever it is you need to write encrypted using a program for one-time pads or just a basic algorithm and then send it in clear text or any other messenger you want. Only people who have access to your pads will be able to decrypt it.