Why Interoperability is the Only Path to True Self-Sovereign Identity

Every protocol—from SpruceID to Veramo—builds its own credential ecosystem. This creates isolated identity silos, defeating the core promise of user-centric data portability.\n- User Lock-in: Credentials issued on one chain are useless on another.\n- Fragmented Reputation: Your on-chain history is split across incompatible ledgers.

No verifier (e.g., a DeFi protocol) will integrate an identity standard without a critical mass of users. No user will adopt a standard without verifiers. This chicken-and-egg problem has stalled every identity project to date.\n- High Integration Cost: Each new standard requires custom engineering.\n- Zero Network Effects: Value accrues to the silo, not the user.

True sovereignty means controlling where your data lives. But interoperability layers like IBC or LayerZero introduce trusted relayers and bridges—new centralization points and attack vectors.\n- Security vs. Sovereignty Trade-off: You either trust a bridge's multisig or stay in your lane.\n- Data Locality Laws: Cross-border credential flows create regulatory minefields.

Interoperability doesn't mean uniformity. Users will be forced to manage multiple W3C VCs, SBTs, and zkProofs across chains, each with different revocation mechanisms and gas costs.\n- Cognitive Overload: Non-crypto-native users will abandon ship.\n- Fee Fragmentation: Paying for attestations on Ethereum, Polygon, and Solana separately.

For SSI to interact with real-world systems (KYC, credit scores), it needs oracles. This recreates the very problem of trusted third parties that SSI aims to solve. Projects like Chainlink become the de facto centralized authorities.\n- Trust Minimization Failure: The oracle's attestation is the single point of truth.\n- Data Freshness: Stale or manipulated off-chain data corrupts the entire graph.

Who pays for interoperability? Issuers won't, verifiers resist, and users expect it free. Without a sustainable economic model, cross-chain identity layers become public goods begging for funding—a historically failed model in crypto.\n- Misaligned Incentives: Value capture is indirect and diffuse.\n- Protocol Sustainability: See the graveyard of layer 2 governance tokens.

Your on-chain reputation, credentials, and assets are trapped in silos. A Gitcoin Passport on Ethereum is useless for a lending protocol on Solana. This fragmentation destroys composability and user agency.\n- Friction: Re-verification required on every chain.\n- Inefficiency: Duplicative KYC/AML checks cost users time and protocols money.

True self-sovereignty requires a portable identity layer that works across any blockchain or application. This is not a single protocol, but a standard—like W3C Verifiable Credentials—enforced by cross-chain messaging.\n- Portability: Your proof-of-personhood from Worldcoin works on Avalanche and Arbitrum.\n- Composability: Build a unified credit score from activity on Aave, Compound, and Solend.

Bridging identity data cannot mean exposing it. Interoperability must be privacy-preserving by default, using ZK-proofs to share attestations (e.g., "is over 18") without revealing underlying data.\n- Selective Disclosure: Prove membership in a DAO without revealing your wallet.\n- Sybil Resistance: Leverage Iden3 or Sismo ZK proofs across ecosystems.

An interoperable identity graph becomes a foundational financial primitive. It enables undercollateralized lending, personalized DeFi yields, and seamless credential-based airdrops across any chain—turning identity into composable capital.\n- Capital Efficiency: Borrow against your on-chain reputation score.\n- Cross-Chain Airdrops: Projects like LayerZero and Wormhole can target users based on multi-chain activity.

Standards like EIP-7212 (for secp256r1) and cross-chain attestation networks (Hyperlane, Axelar) are the battleground. The winner won't be a single identity app, but the interoperability layer that becomes the TCP/IP for identity.\n- Standardization: Secure enclave signatures verifiable everywhere.\n- Network Effects: The most connected attestation graph becomes the default.

Interoperability flips the model: instead of platforms owning your data, you own and monetize your graph. You license your gaming achievements from Immutable to a betting dApp on Polygon.\n- New Revenue Streams: Users earn fees for verified data access.\n- Anti-Fragility: Your identity persists even if one chain or app fails.