ENS Domain for Metadata

ENS text records provide a simple, on-chain key-value store for verifiable claims. Organizations or protocols can issue attestations by writing to a user's ENS domain. Common examples include:

• Proof-of-personhood or KYC status
• Membership tokens for DAOs or communities
• Skill certifications or completion badges These records enable trust-minimized verification without relying on a central database, as the proof is stored on the user's own sovereign identity.

ENS metadata dramatically improves user experience in wallets and payment systems. Key implementations include:

• Human-readable send-to addresses, eliminating the risk of copy-paste errors with long hexadecimal addresses.
• Transaction intent clarity, where a wallet can display the resolved avatar and name of the recipient before confirming.
• Cross-chain payments, where a payer only needs the recipient's .eth name, and the wallet resolves the correct chain-specific address from metadata.

ENS domains are used as the public identity for Decentralized Autonomous Organizations (DAOs) and protocols. The associated metadata is critical for:

• Official communication, using the domain for websites and documentation.
• Treasury management, where a multisig wallet address is linked to treasury.dao.eth.
• Governance delegation, where delegates can link their forum profiles and statements to their ENS name.
• Brand verification, allowing community members to easily verify official social channels and announcement sources.

The file the content hash points to must follow a structured schema for interoperability. Common standards include:

• ERC-721/1155 Metadata Standards: For NFTs, with fields like name, description, image, and attributes.
• Custom Protocol Metadata: For DAOs or DeFi protocols, including protocolName, version, logo, and links to documentation or interfaces.
• The image and other assets should also use decentralized URIs (e.g., ipfs://...).

For complex systems, a root domain (e.g., protocol.eth) can delegate subdomains to different resolvers.

• Create subdomains like governance.protocol.eth or vaults.protocol.eth.
• Set individual resolvers for each, allowing separate teams or contracts to manage their own metadata records.
• This enables a scalable, modular architecture where different protocol components have their own verifiable data endpoints.

Smart contracts can programmatically verify and use ENS metadata.

• Read the resolver: Use the ENS registry's resolver() function to get the resolver address for a name.
• Fetch records: Call the resolver's methods (e.g., text(), contenthash()) to retrieve data on-chain.
• Use Cases: Verify a DAO's treasury address, confirm a token's official artwork URI, or gate permissions based on a verified text record.

ENS resolution is a hybrid system. While the .eth registry is on Ethereum, the resolver contract that points to your metadata (e.g., a JSON file) can be a standard, centralized web2 URL. This creates a single point of failure if the hosted file is taken down or altered. Using a decentralized storage resolver (like IPFS or Arweave) is more resilient but requires careful management of the content hash.

The security of the metadata link depends entirely on the resolver contract set for the ENS name. Key risks include:

• Owner Compromise: If the private key for the ENS name's owner is lost or stolen, an attacker can change the resolver.
• Resolver Upgradeability: Some resolver contracts are upgradable by an admin key. If compromised, the admin can redirect all metadata pointers.
• Best Practice: Use a simple, audited public resolver or a non-upgradable custom resolver, and secure the owner keys with a multisig or hardware wallet.

There is no native cryptographic link between the ENS record and the content it points to. Without additional verification, users must trust that the hosted metadata has not been altered. Mitigation strategies include:

• Content Hash Field: Using the contenthash field to store an IPFS or Swarm hash, which cryptographically guarantees the content.
• On-Chain Signatures: Having the metadata signed by a known developer key, with the signature and public key included in the smart contract for verification.

Applications (dApps) that fetch and display ENS-linked metadata introduce their own risks:

• Gateway Reliability: If using IPFS, the dApp relies on specific HTTP gateways (like ipfs.io) which can be blocked or suffer downtime.
• Javascript Injection: The dApp's frontend code fetching the JSON is a potential attack vector for malicious code injection if the metadata server is compromised.
• Caching Issues: Aggressive caching by gateways or CDNs can serve stale or incorrect metadata after an update.

Projects often create subdomains (e.g., app.project.eth) for different features or versions. Security depends on the delegation model:

• Owner-Controlled: The root domain owner retains control, creating a centralization risk.
• Controller-Delegated: A separate controller address can update subdomain records, which must be tightly secured.
• A compromised subdomain controller can point metadata to malicious data, affecting all users of that specific service without affecting the main domain.

For non-.eth names (like .com, .xyz via DNS integration), security inherits from the traditional DNS system and the DNSSEC oracle.

• DNS Vulnerability: The linked metadata is only as secure as the underlying DNS record, which is susceptible to registry compromise, registrar hijacking, or DNSSEC failures.
• Oracle Reliability: The ENS DNSSEC oracle must correctly validate and publish proofs. Users must trust this oracle's operation and the multi-sig controlling it.