When someone writes something on a piece of paper, puts that piece of paper in a box, and later I see someone reopens that piece of paper then I can be reasonab

When someone writes something on a piece of paper, puts that piece of paper in a box, and later I see someone reopens that piece of paper then I can be reasonably confident I see whatever the original person wrote on the piece of paper. I have no such confidence in electronic messages. Unless they're plaintext.