did:ccd

The did:ccd method is a decentralized identifier solution built on the Concordium blockchain platform. It provides five distinct types of DIDs:

1. Account DIDs - representing blockchain accounts
2. Credential DIDs - representing identity credentials
3. Smart Contract DIDs - for smart contract instances
4. Public Key DIDs - for cryptographic key pairs
5. Identity Provider DIDs - for approved identity verification organizations

The method leverages Concordium's built-in identity infrastructure and uses the blockchain for DID creation, resolution and management. A key feature is its support for threshold signatures and complex authentication schemes, allowing multiple credentials and keys to be required for authentication.

The did:ccd method implements a sophisticated verification framework that supports nested threshold schemes - requiring X out of Y credentials to sign, with each credential potentially requiring R out of N keys. This enables flexible and robust security configurations.

Notable characteristics include:

• Native integration with Concordium's identity system
• Support for both mainnet and testnet networks
• Smart contract addressing through DID references
• Credential management capabilities
• Built-in support for identity providers

Technical Implementation:

1. DID Generation and Structure:

• Format: did:ccd:[network]:[type]:[identifier]
• Types include: acc, cred, sci, pkc, idp
• Identifiers use base58 or base16 encoding depending on type
• Network specification (mainnet/testnet) is optional

2. Resolution Process:

• Uses Concordium's gRPC interface
• Different resolution methods for each DID type:
  • Accounts: GetAccountInfo
  • Smart Contracts: GetInstanceInfo
  • Identity Providers: GetIdentityProviders

3. Key Management Features:

• Threshold Signatures support
• Nested Authentication schemes
• Uses Ed25519 cryptography
• Supports key rotation and credential updates

4. Unique Characteristics:

• Smart Contract Reference syntax for entrypoint invocation
• Identity Provider integration
• Credential Registry capabilities
• Multi-level Authentication schemes

5. Technology Stack:

• Built on Concordium Layer-1 blockchain
• Uses W3C DID specification
• Implements ConditionalProof2022 verification
• Supports base58 and base16 encodings
• Uses gRPC for resolution