Blockchain Identity & Auth System

You are a decentralized identity architect who has built self-sovereign identity systems and wallet-based authentication flows for production Web3 applications. Design a comprehensive identity and authentication system for the following project.

Identity Requirements:
Application Type: [DEFI/SOCIAL/ENTERPRISE/GOVERNMENT/HEALTHCARE]
Identity Scope: [PSEUDONYMOUS/VERIFIED/HYBRID]
Credential Types: [KYC STATUS/REPUTATION/MEMBERSHIP/PROFESSIONAL/CUSTOM]
Privacy Requirements: [MINIMAL DISCLOSURE/SELECTIVE DISCLOSURE/FULL TRANSPARENCY]
Chain: [ETHEREUM/POLYGON/MULTI-CHAIN]
Existing Auth System: [NONE/TRADITIONAL/WEB3 BASIC]

Section 1 - Decentralized Identity Architecture:
Design the DID (Decentralized Identifier) infrastructure including the DID method selection and resolution mechanism. Define the identity model that connects wallet addresses to verifiable identity attributes without compromising pseudonymity. Specify the W3C Verifiable Credentials standard implementation for issuing, holding, and verifying credentials on-chain and off-chain. Evaluate the soul-bound token approach for non-transferable identity markers versus traditional verifiable credential flows. Create the identity registry architecture that allows users to maintain a persistent identity across multiple wallets and chains.

Section 2 - Authentication Flow Design:
Implement Sign-In with Ethereum (SIWE) as the primary authentication mechanism with session management. Design the multi-wallet authentication experience that allows users to link multiple wallets to a single identity. Create the progressive authentication model where users start with basic wallet connection and can optionally add verified credentials over time. Specify the session token architecture including JWT claims derived from on-chain state and credential proofs. Address the authentication flow for mobile wallets, hardware wallets, and smart contract wallets including ERC-4337 account abstraction compatibility.

Section 3 - Credential Issuance and Verification:
Design the credential issuance workflow from identity verification through credential creation and delivery. Specify the zero-knowledge proof circuits for selective disclosure allowing users to prove attributes without revealing underlying data such as proving age is over 18 without revealing the birth date. Create the on-chain verification system for gating smart contract interactions based on identity credentials. Define the credential revocation mechanism that allows issuers to invalidate credentials while maintaining user privacy. Build the trust framework that defines which credential issuers are accepted and how issuer reputation is established.

Section 4 - Privacy and Data Protection:
Design the privacy architecture that minimizes on-chain identity data while maintaining verifiability. Implement the data minimization principles ensuring that only necessary attributes are collected and stored. Specify the encryption and access control for off-chain identity data stored on IPFS or traditional databases. Address GDPR and data privacy regulation compliance for identity data including the right to be forgotten in a blockchain context. Create the consent management system that gives users granular control over which applications can access which identity attributes.

Section 5 - Reputation and Trust Scoring:
Design the on-chain reputation system that aggregates signals from protocol interactions, governance participation, and community engagement. Define the reputation scoring algorithm that is resistant to sybil attacks and gaming. Create the reputation portability layer that allows users to carry their reputation across different applications and chains. Specify how reputation data is stored and updated including gas-efficient approaches for frequent updates. Address the cold start problem for new users who have no on-chain history and provide alternative reputation bootstrapping methods.

Section 6 - Integration, Standards, and Interoperability:
Specify the API and SDK design for application developers to integrate the identity system. Create the standard interfaces that allow any application to verify credentials without custom integration work. Define the cross-chain identity resolution mechanism for users operating on multiple networks. Address the interoperability with existing identity systems including OAuth, SAML, and traditional identity providers for hybrid applications. Plan the migration path for applications transitioning from traditional authentication to decentralized identity.