This is a project that spun from my frustrations of using LocalSend and DashBeam to transfer stuff between devices, and with the extra goal of being fast, trying out the Slint framework and, most importantly, establishing a communication channel with trusted external people that can be left always on. |
The heavy lifting is done in this function, pairing. You link your personal devices together, solid idea [0].
This Flipflop project relies on the Iroh library for NAT/Firewall puncturing, external address discovery and overlay networking. Connecting two 5G devices, without a coordinating central server is possible, but very hard. Iroh simply relies on a server which you could self-host. Cool stuff, we stress tested it a while ago and it somewhat worked.
NAT connectivity is unsolved. My university lab conducted one of the bigger puncturing studies a decade ago [1]. Recently, we also bought 40+ or something 4G and 5G SIM cards in Europe for puncturing [2]. My master student traveled Europe by bus to get these local SIM cards. He worked day-and-night to connect these weird symmetric 5G NAT filter boxes and got it working. Simple sync collision and birthday paradox brute force... It all works sometimes, but insufficiently reliable for mass-adoption. You can't build a decentralized social media ecosystem on top. Like Iroh, best to use a central server. So then you have legal liability for your users. Unless an AI agent buys the server fully autonomously using Bitcoin, next years students got that working[3] :-)
[0] https://github.com/andunieee/flipflop/blob/62bb498520aacb60e...
[1] UDP NAT and Firewall Puncturing in the Wild, https://inria.hal.science/hal-01597969v1/document
[2] Mass Adoption of NATs: Survey and experiments on carrier-grade NATs, https://arxiv.org/html/2311.04658v2
[3] Self-replicating seedbox servers using programmable money, https://arxiv.org/abs/2609.05431
So if you are in an extremely weird NAT you will fall back to a relay, either our public relays, your own relays rented from us via iroh services, or a self-hosted relay.
But I would argue that a p2p social application that occasionally uses a relay is very much preferable to a centralised app.
The relay is generic internet infrastructure. It just forwards end to end encrypted connections. It can not learn anything about the content.
A relay that is hosted on a non KYC server rented via ZCash would be interesting though if you are super paranoid.
By 2030 we hopefully understand the mathematics-of-trust and can link all the billions of citizens together in a single overlay.
> non KYC server rented via ZCash would be interesting though if you are super paranoid.
What will happen if a decentralized Internet emerged and presented an existential threat to existing profit margins? Company lawyer would start to attack you, correct?
You can, ATProto has the example schematics for how, but it's has a federated rather than distributed architecture, but I don't think "federation" is a hard constraint of the design, more like an implementation detail, and as long as you can do the signalling centrally, to connect the peers, you can do the rest P2P. So sure, legal liability for the connection of peers, but all data transfers would still be directly P2P. AFAIK, Iroh also does "Centralized signaling > P2P data transfers", even when NAT is in the way.
I guess it's a bit like comparing WeTransfer with Airdrop, one tries to use the network they're on already (internet) where the other favors local-local connections.
Nice idea with the browser link to share with devices that dont have flipflop on the same LAN. This would be a killer if this would also work via internet! Not sure if Iroh can run in the browser though.
I would think this could be done completely in the browser using WebRTC?
But iroh is designed bare metal first, we currently support the browser via WASM, but only with relay mode.
We will solve browser eventually, but I think it is a mistake to build peer to peer tech browser first. We think it is better to make it extremely efficient on bare metal first, and then grow into the restricted browser ecosystem where possible.
Browsers are very restricted environments.