>>concor+yp
I don't have time anymore today to get into lots of details about saving communication online but I liked how in Neal Stephenson's "Fall, or, Dodge in Hell," internet identity was basically completely wiped out by the proliferation of bots, and identity had to work off of chains of subtle identity attributes that were cryptographically strong because... scifi magic with lots of Stephenson description, you might be smarter than me in that field so give it a pokearound.
Doctorow in "Walkaway" had some ideas about it that I liked as well.