Web DID

DIDs enable a persistent, user-owned identity across games and virtual worlds. This allows for:

• Portable Assets & Achievements: NFTs and accomplishment badges are tied to your DID, not a platform account (e.g., Xbox Live, PlayStation Network).
• Proven Skill & Reputation: A player's skill rank or tournament history can be issued as VCs, verifiable in any game.
• Interoperable Avatars: A user's DID can be linked to a 3D avatar asset that works across different metaverse environments.

The security of a DID is fundamentally tied to the protection of its associated private keys. Loss or theft of these keys equates to a complete loss of identity control. Best practices include:

• Using hardware security modules (HSMs) or secure enclaves for key generation and storage.
• Implementing multi-signature schemes or threshold signatures to distribute trust.
• Employing key recovery mechanisms (e.g., social recovery, Shamir's Secret Sharing) that do not reintroduce central points of failure.

The DID Document contains the public keys and service endpoints for a DID. Its integrity must be guaranteed by the underlying verifiable data registry (e.g., a blockchain). Security considerations include:

• Ensuring the registry provides cryptographic immutability and tamper-evidence for published DID Docs.
• Managing DID Doc updates and deactivation securely to prevent unauthorized changes.
• Verifying that the registry's consensus mechanism is resistant to Sybil attacks and 51% attacks that could compromise the ledger's state.

DID-based ecosystems are not immune to human-factor attacks. Users may be tricked into signing malicious transactions or revealing sensitive information. Critical defenses are:

• Verifiable Credentials (VCs) with cryptographic proofs to establish authentic communication channels.
• User-agent wallets that clearly display the semantics of a signature request (e.g., "Signing to login to app X").
• Education on recognizing and avoiding phishing attempts targeting seed phrases or authorization prompts.

The value of a DID is realized through interoperability across different systems (W3C, DIDComm, OIDC). This introduces security challenges:

• Protocol-level vulnerabilities in cross-system communication layers like DIDComm.
• Trust establishment in a decentralized context; determining which Issuers and Verifiers are credible.
• Adherence to governance frameworks (e.g., GAIN, Trust over IP) that define security and operational baselines for participants in the ecosystem.

While DIDs enable pseudonymity, poor practices can lead to identity correlation and privacy leakage. Key risks and mitigations include:

• DID method-specific identifiers that may be globally unique and persistent, creating correlation vectors.
• Using pairwise-unique DIDs for different relationships to prevent cross-context tracking.
• Employing zero-knowledge proofs (ZKPs) within Verifiable Credentials to disclose only necessary attributes (e.g., proving age > 18 without revealing birthdate).

The ability to revoke compromised credentials or deactivate a DID is a core security requirement. Challenges include:

• Revocation mechanism design: Options include status lists (2021), cryptographic accumulators, or ledger-based revocation registries, each with trade-offs in privacy, cost, and timeliness.
• Real-time status checking: Verifiers must have a secure, reliable method to check the revocation status of a presented credential.
• Persistence of historical data: Ensuring deactivated DIDs or revoked credentials cannot be fraudulently presented as valid from a historical snapshot.

User agents that allow individuals to create, store, and manage their DIDs and associated Verifiable Credentials (VCs). These wallets are the primary interface for Web DID adoption, enabling users to:

• Securely store private keys for signing and authentication.
• Present selective credentials (e.g., proof of age) without revealing the entire document.
• Interact with DID resolvers and verifiable data registries to prove identity claims.

Examples include mobile apps like Trinsic, SpruceID, and browser extensions.

The core utility of DIDs is issuing and verifying tamper-proof digital attestations. A Verifiable Credential is a cryptographically signed statement (e.g., a university degree) from an issuer. Key mechanisms include:

• Selective Disclosure: Using zero-knowledge proofs (ZKPs) to prove a claim (e.g., 'over 21') without revealing the underlying data.
• Holder-Binding: Ensuring credentials are uniquely linked to the DID of the holder, preventing transfer or forgery.
• Revocation Registries: Allowing issuers to revoke credentials without compromising user privacy.

DIDs enable passwordless, phishing-resistant logins across web services. The Sign-In with Ethereum (SIWE) standard is a prominent implementation, where users:

• Authenticate by signing a cryptographic challenge with their Ethereum wallet's private key.
• Prove control of a DID tied to their Ethereum Address (e.g., did:ethr:0x...).
• Share a public profile without relying on centralized platforms like Google or Facebook. This provides a seamless, self-custodied alternative to OAuth for dApps and traditional websites.

DIDs form the identity layer for user-centric social graphs and reputation protocols. Applications include:

• Decentralized Social Networks (DeSo): Platforms like Farcaster and Lens Protocol use DIDs as persistent, portable user identities, separating social data from the application layer.
• On-Chain Reputation: Accumulating verifiable attestations (e.g., governance participation, loan repayment history) linked to a DID, creating a portable reputation score.
• Sybil Resistance: Using proof-of-personhood or proof-of-uniqueness credentials to prevent bot attacks in governance and airdrops.

Businesses adopt DIDs for streamlining compliance and proving authenticity in complex workflows. Use cases involve:

• Know Your Customer (KYC): Users obtain a reusable, privacy-preserving KYC credential from a regulated issuer, which can be presented to multiple financial services.
• Supply Chain Provenance: Each entity (manufacturer, shipper, retailer) in a supply chain has a DID. Verifiable Credentials are issued at each step (e.g., did:example:factory attests to organic certification), creating an immutable audit trail.
• Professional Credentialing: Instant verification of employee qualifications and professional licenses.

Widespread adoption relies on standardized protocols for DID methods, credential formats, and trust frameworks. Key governing bodies and specifications include:

• W3C DID Core Specification: Defines the foundational data model and operations for all DIDs.
• DID Methods: Implementation-specific rules (e.g., did:ethr, did:key, did:web) for creating and resolving identifiers on different networks.
• Verifiable Credentials Data Model (VCDM): The W3C standard for creating, transmitting, and verifying credentials.
• Decentralized Identity Foundation (DIF): A consortium driving the development of interoperable identity infrastructure.