>Make secure software that is simple to implement, simple to use, and hard to misuse (it's not that hard dammit, just look at qmail).I made a previous comment about this being a hard problem[1]. If competent ultra techno geeks can get hacked, the problem looks to be unsolvable for the general homeowner to safely run a p2p server.
Many recurring security+usability problems that nobody has solved in the general case. Examples... Heartbleed SSL bug that's undetected for 2 years before being fixed, social engineering, homeowner misconfiguration, p2p server data not being backed up, software updates as an attack vector for decreasing security instead of hardening security, etc.
If my grandmother asked me, "A friend said I can share cooking recipes if I install a p2p food wiki server, what do you think?" I would immediately say "No! Don't install it. I will find you a _centralized_ web recipes forum for you to log in to!"
I ran qmail on my home server in the 1990s to personally control my SMTP needs which should theoretically make me the biggest cheerleader for a "p2p food wiki server". Instead, it informs my position to stop my family members from installing p2p software. Think about why I would do that.
The "symmetric bandwidth" isn't the only underlying problem.
>That problem is never worse with P2P protocols.
Everything has tradeoffs -- including p2p. Otherwise, you have an incomplete picture that doesn't consider pros and cons. P2p is worse for latency, worse for analyzing a unified network landscape to identify and filter out hostile actors, worse for non-techie usability, worse for instantaneous propagation of software updates to fix zero-day exploits, worse for homeowner costs, etc. There isn't a "set & forget" p2p appliance you can build that solves all of that. BitTorrent gets around the negatives of p2p because the value of the data users transfer (pirated Star Wars movies or Adobe software etc) overrides the hassles.
[1] https://news.ycombinator.com/item?id=11861683