dcipher ceremonies

This repository contains all material relating to dcipher network ceremonies, including instructions, transcripts and public key material.

Purpose

The asynchronous distributed key generation (ADKG) ceremony is a decentralized cryptographic setup protocol executed by a set of nodes to jointly generate a shared public/private key pair without relying on a trusted dealer.

In the context of the dcipher network, this ceremony bootstraps a threshold cryptography network that allows nodes to later perform collective operations like decryption or signing, where a subset of nodes (e.g. 3-of-7) can act on behalf of the group.

This is based on the paper Practical Asynchronous Distributed Key Generation by Das et al., and the adkg-cli tool from the dcipher repo implements this process.

Phases

The ADKG ceremony consists of three stages:

• Scheme Definition: One participant (henceforth referred to as 'the leader') defines and shares a scheme file that outlines the curve parameters, and generators, and shares it with the other participants.
• Operator Key Generation: Each participant generates two long-term keypairs (ADKG and libp2p) and submits their public key material to the leader, whereby the leader will create a group file. (They can also broadcast it to the other participants for the sake of verifiability.)
• Distributed Key Generation: All nodes run the ADKG protocol simultaneously using synchronized start time, scheme definition and shared group file, producing a distributed public/private keypair suitable for threshold cryptographic operations.

Runbooks

This directory contains a variety of runbooks for operators and leaders.

Operators

• Installing the DKG CLI
• Operator Key Generation
• Before the Ceremony (Operator)
• During the Ceremony (Operator)

Leaders

• Before the Ceremony (Leader)

Schemes

A scheme is used to describe an instance of the ADKG. It contains various parameters, such as the curve, curve parameters, and the version. Here is an example of a scheme specification used in the context of dcipher:

app_name = "dcipher"
curve_id = "Bn254G1"
hash_id = "Keccak256"
adkg_version = "v0.1"
adkg_scheme_name = "DYX20-Bn254G1-Keccak256"
generator_g = "qB3/U8RDVn4aF2tUTlmeDQbV0PvHJ8IB0QL/k1Z+5WI="
generator_h = "gAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAE="

The new-scheme command can be used to obtain a scheme specification as follows:

adkg-cli new-scheme --app-name dcipher --out scheme.toml

By default, we use the DYX20-Bn254G1-Keccak256 scheme. This represents the aforementioned ADKG, using the bn254 curve on group G1. In this configuration, the long-term public keys use a deterministic generator, H, obtained by hashing ADKG_GENERATOR_G with the DST ADKG-%adkg_version%-%app_name%_BN254G1_XMD:KECCAK-256_SVDW_RO_GENERATORS_ using rfc9380. The public keys after the ADKG, however, are output with respect to the standard generator of bn254, the point (1, 2).

It is preferable that a single participant executes the new-scheme command, and sends the generated file to the rest of the participants.