Velocity

Intro to Velocity Network

Velocity Network Foundation

Velocity NetworkTM is a public permissioned distributed network, based on a permissioned version of the Ethereum Blockchain utilizing Hyperledger Besu. Operating a node and writing to the Velocity Ledger requires permission from the Velocity Network FoundationR.

The following data is stored on chain:

• organization metadata - DID, profile, endpoint

• credential metadata (encrypted) - ID, type, public key, revocation status

• verification voucher transactions

• credential types and schemas

Network participants

High level

• Holder - a person that holds the credential on behalf of the subject (themselves or another person)

• Issuer - an organization that creates and issues credentials

  • first party issuer - an entity that can directly attest to the claims within the credential

  • notary issuer - an entity that can evaluate evidence to attest to the claims within the credential

• Relying Party - an entity that requests and verifies credentials from a Holder

Low level

• Wallet Provider (Holder App Provider) - an organization offering digital wallets to be used by Holders

• Credential Agent Operator - an organization operating a credential agent

  • Agent - an interface to the network used by organizations (Issuer, Relying Party, Holder) - call contracts, retrieve account states - form the 'layer-2' network

    • Tenant - an organization’s delegate on which behalf the agent is acting

• Node Operator - an organization operating a node

  • Node - a participant on the network holding copies of the underlying ledger

    • Members (Stewards) - read-only nodes with limited data access that forward write operations to Validators

    • Validators - full-write permission nodes that participate in consensus

• Velocity Network Registrar - a set of centralized services that are used for administering the accredited organizations and credential types on the Network

• Credits hub - a module where Velocity credits are administered and credit reward transactions can be executed

• Voucher hub - a module where Velocity vouchers are administered and top up transactions can be executed

• The ledger - the distributed blockchain-based, continuously-replicated, global cryptographic database maintained by Stewards operating nodes communicating with the Velocity consensus protocol

Workflows

• Issuing - the process of asserting claims about a Holder who receives the verifiable credential

  • by writing a transaction to the Velocity Ledger which includes the credential ID, its type, the Issuer ID, and the public key matching the private key that signed it

• Revocation - the act of an Issuer revoking the validity of a credential

  • by writing a transaction to the Velocity Ledger marking the credential as revoked

• Verification - the process of confirming that a verifiable credential is not modified, revoked or expired and is issued by a trusted authority

  • by accessing the Velocity Ledger to retrieve the unique public key associated with credential and verify its signature

Verifiable Credentials

Velocity currently uses the JWT format for encoding credentials with JWS signatures using SECP256K1 as proofs.

Verifiable credentials are divided into the following categories:

• Layer-1 credential types - network’s core set of credential types (e.g. Email, IdDocument, OpenBadgeCredential)

  • for each issued credential, the Issuer receives a reward in the form of Velocity Credits

• Layer-2 credential types - any custom credential type

  • should be mapped to a Layer-1 type in order for the Issuer to be eligible for a reward

More about credential types here https://docs.velocitynetwork.foundation/docs/developers/basics-credential-types.

Decentralized identifiers

• did:ion - used to identify organizations or individuals

  • received when registering with the Registrar

• did:velocity - used to identify credentials

  • is immutable

  • stores only a single key and credential type

  • resolving it will burn an NFT to permit DID resolution