Attestation Types

FDC Attestations provide cryptographic proofs for data originating outside Flare's EVM state. They enable smart contracts to verify external data trustlessly. For example, FDC attestations can validate:

• Non-Payment Verification: Confirm whether a payment has not been made on a UTXO chains like Bitcoin or Dogecoin.
• Event Log Authentication: Verify event logs generated by transactions on EVM-compatible blockchains.

FDC currently supports the following six attestation types:

AddressValidity

Assertion whether a given string represents a valid address on an external blockchain.

BalanceDecreasingTransaction

Detects a transaction that either decreases the balance of a specified address.

ConfirmedBlockHeightExists

Assertion whether a specified block number is confirmed.

EVMTransaction

Information about an EVM transaction, including details on associated events if specified.

Payment

Information about a transaction on an external chain that is classified as a native currency payment.

ReferencedPaymentNonexistence

Assertion that a payment agreed to be completed by a certain deadline, has not been made.