I wrote a blog post about frost https://www.iroh.computer/blog/frost-threshold-signatures

For iroh, we use curve ed25519, while nostr is using secp265k1. So the linked code only works with ed25519 keys.

But other than that this transfers 1:1. You can take an existing key and split it into as many key shares as you want. So you can move to a multisig style approach while preserving your nostr identity.

You could take the existing code, replace https://crates.io/crates/frost-ed25519 with https://crates.io/crates/frost-secp256k1, and you would have a working co-signing setup for nostr keys. 

 I am new to nostr. I guess I have to set something up?

Anyway, the cryptography is solid, it’s from the zcash foundation https://zfnd.org/ , and the crates make a good impression in my opinion. 

 Iroh dev here.

The core of iroh is p2p QUIC with dial by node id and very good NAT hole punching, so you almost always get direct connections.

We need a global mechanism to publish some information (a relay URL and optional direct addresses) for an ed25519 public key.

We have multiple mechanisms, one of them pkarr.

So far it works really, really well. Both speed and reliability is comparable to DNS, but we don’t have to run infrastructure. It is just nice in terms of operations even if you don’t care about p2p for ideological reasons.

See https://docs.rs/iroh-net/latest/iroh_net/discovery/index.html