Create

Creating a did:btcr2 identifier from an secp256k1 public key will result in an Initial DID Document when first resolved. Creating a did:btcr2 identifier from a Genesis Document allows for the creation of a more complex Initial DID Document, including the ability to include service endpoints and BTCR2 Beacons that support aggregation. Any active did:btcr2 DID document can be updated later with new key material and service endpoints.

Process

A did:btcr2 identifier encodes a few pieces of information: an indicator for a specific Bitcoin network and a collection of Genesis Bytes. A specification version number is also included. These three values are encoded with the DID-BTCR2 Identifier Encoding algorithm.

The Genesis Bytes can be created in two ways: from an secp256k1 public key or from a Genesis Document.

secp256k1 Public Key

An secp256k1 public key can be used as the Genesis Bytes. The key MUST be in its compressed SEC format: a 33-byte representation consisting of a single prefix byte (0x02 or 0x03) followed by the 32-byte x-coordinate of the elliptic curve point. Reference Section 2.3.3 in SEC 1: Elliptic Curve Cryptography [SEC].

Genesis Document Hash

A Genesis Document can be used as the Genesis Bytes, but MUST be hashed to 32 bytes with the JSON Document Hashing algorithm.