Bluntly: Serverless, NAT-breaking P2P with public keys and BitTorrent DHT (opens in new tab)

That's a good point. You still need those. I don't believe there's any way around it whenever you're using a decentralized network like the DHT, you need to somehow "get into" the network, so you need to know someone from it.

Well BitTorrent's own project Bleep uses the Bittorrent network as well.

Their protocol is more complex however. Their goals are to hide who is talking who, from entities that might just be scraping the DHT. With bluntly, you can tell who is talking to who, by looking at what peers advertised on the rendezvous node.

Because they have control over the bittorrent protocol, they can go ahead and make changes to it that make NAT penetration easier (a 3rd party peer with a public address acts as a facilitator for putting 2 peers behind NAT in contact) or they can allow for arbitrary data to be stored in the DHT.

I do the same in rakoshare (https://github.com/rakoo/rakoshare). Humans exchange a well-known id, from which a rendez-vous id is derived. This rendez-vous id is used for all interested peers to meet and exchange ips and ports.

After that, it's the job of every one to try to connect to the other side. Sadly, if there's a NAT on each side, it's not enough...

Retroshare uses Bittorrent DHT http://retroshare.sourceforge.net/

retroshare uses DHT

It also uses PGP keys to facilitate encryption, authenticity, and a comprehensive web of trust