TAANQ Attestations¶

TAANQ Attestations are on-chain records that confirm the authorship of a specific piece of content at a particular point in time.

Each attestation links a content identifier (IPFS CID) to an authority address, recording when that authority acknowledged authorship of that content. Attestations are immutable once created, though they can be revoked within a 7-day window.

Data Model¶

struct Attestation {
    bytes32 ipfsHash;        // IPFS CID of the attested content
    bytes32 qvHash;          // Quote-verification hash
    bytes32 parentIpfsHash;  // Optional: CID of a prior version (for edits)
    address authority;       // Address that made the attestation
    uint256 timestamp;       // Block timestamp when the attestation was created
    uint256 revokedAt;       // Block timestamp of revocation; 0 if not revoked
}

Attestations are stored in a public array on the contract. The array is pre-initialized with a placeholder at index 0 so that all real attestations start at index 1. An index of 0 therefore means "no attestation found."

Fields¶

Lookups¶

Two mappings allow efficient on-chain lookups without iterating the full attestation array.

// All attestation indices for a given IPFS CID
mapping(bytes32 => uint256[]) public cidToAttestationIndices;

// The single attestation index for a given CID + authority pair
mapping(bytes32 => mapping(address => uint256)) public cidAndAddressToAttestationIndices;

• Use cidToAttestationIndices[ipfsHash] to retrieve an array that contains all attestation indices for a piece of content. You will need to provide an index in this list to get a specific attestation index, and then use that index to look up the attestation in the main attestations array.
• Use cidAndAddressToAttestationIndices[ipfsHash][authority] to look up whether a specific authority has attested to a specific piece of content, and retrieve that attestation's index directly.

Creating an Attestation¶

Creating an attestation uses the commit/reveal scheme to prevent front-running. The full flow is:

1. Commit — Call commit(saltedHash) where saltedHash = keccak256(abi.encodePacked(ipfsHash, bytes32(bytes20(msg.sender)), salt)).
2. Wait — Wait at least 60 seconds after the commit is mined.
3. Reveal — Call reveal(...) with the original values to create the attestation.

reveal()¶

function reveal(
    bytes32 saltedHash,
    bytes32 salt,
    bytes32 ipfsHash,
    bytes32 qvHash,
    bytes32 parentIpfsHash,
    address authority
) external

Validation:

• The salted hash must match keccak256(abi.encodePacked(ipfsHash, bytes32(bytes20(msg.sender)), salt)).
• The commit must exist and be at least 60 seconds old.
• If authority != msg.sender, a valid delegation must exist.
• An attestation for the same ipfsHash + authority pair must not already exist.

On success, the commit is deleted (returning a gas refund) and the attestation is appended to the attestations array.

Revoking an Attestation¶

function revokeAttestation(uint256 attestationId) external

An attestation can be revoked by its authority address or a current delegate of that authority. Revocation sets revokedAt to block.timestamp.

Constraints:

• The attestation must have been created within the last 7 days (DEFAULT_REVOCABLE_WINDOW = 604800 seconds).
• The attestation must not already be revoked.

After the 7-day window closes, an attestation becomes permanent and cannot be revoked.

Constants¶