end-to-end encryption

[Julian-Dumitrascu]

@kepano It seems you have stated something that can be construed like this: One can encrypt data only in a computer program installed on a computer of size 3 (e.g. a laptop computer) or of size 4 (a desktop computer).
I don't know that one can use your program Obsidian together with another human being. Allowing for anonymous reading is too little. They say that people can use some programs to have communication that is encrypted fully. Among them, developers that let us use their software in a Web browser. Well, it matters less whether one interacts with a program through a Web browser or through an operating system; I refer to developers who state that they offer end-to-end encryption of user data while they store these data. Because such a statement seems different from yours, I share that I want to find out what the truth is.
Can one encrypt one's data fully with a program only on computers one really controls? Must these data be stored on the computer on which the program is installed? I hope that one can choose the best storage services. For this, data would have to be encrypted whenever necessary, wherever they are: in a certain computer or between various devices from the Internet.
I'd like to find out to what extent encryption is possible. I'd like any number of people to be able to manage data together over the Internet while their programs let them choose who does what with their data and let them know who does what with their data.
What makes you interested in this topic?
What do you want from data management?
This conversation can help you, me, and anybody else improve computing.