Adding VRF-based computation of labels

Jasleen1 commented 3 years ago

We want to use a VRF to compute labels in seemless_directory.rs and then verify these VRFs in lookup_verify, key_history_verify etc.

See: https://crates.io/crates/vrf for one option. Below is a starting checklist of things to consider:

[x] We will need to convert the output of the VRF into NodeLabel type. We may want to change the NodeLabel type as a result, or implement a trait instead.
[ ] VRF keys need to be stored in some sort of config file, so that the server can generate VRF values.
[ ] In the Java implementation of SEEMless, we used BouncyCastle, and at the time, we had to hash to the curve from strings/bytearrays. We need to hash to the correct space in this case as well.
[ ] If we hash to a curve and later hash the output value, we should be careful about the security guarantees offered by the various parameter sizes. Would be helpful to add documentation for this.

slawlor commented 2 years ago

Implementation merged based on ECVRF-ED25519-SHA512-TAI reference. See linked PRs.

@Jasleen1 what's left on the checklist to be done with the landing of VRFs?

kevinlewi commented 2 years ago

I believe this should be done and this can be closed (finally!), but @Jasleen1 to confirm

facebook / akd