I use syncthing for a few days and read the FAQ/docs but I did not find a satisfactory answer to this question.
I want to use synchting in scenarios where I share parts of data with semitrusted partners. Particular examples:
I want one share between my private computer and my work computer. While the work computer should not be able to sync this one folder, it should not be able to access anything else I have shared.
I want to have a shared folder for a group of friends. Clearly they should by no means be able to access my personal files.
Question: When I connect two syncthing instances (e.g. my computer and my friends), I can select under “Sharing” one particular directory. Will this ensure by all means (cryptographically) that my friends computer cannot access any other folders I shared?