Attestation

The attestation subsystem of the Creditcoin Oracle acheives consensus about the confirmed state of a foreign chain. It then records that consensus on Creditcoin.

Attestation is the process by which the Creditcoin Decentralized Oracle keeps track of the finalized state of external source chains. State transitions of each source chain are monitored by a set of attestors. Each attestor submits an attestation, a cryptographic commitment showing their view of new blocks in the source chain. Since no single attestor can be fully trusted, we require consensus among independent attestors.

Attestation Process

The attestation process is roughly outlined below:

• Attestors constantly monitor the source chain for new finalized blocks.

• Attestors then check the Creditcoin chain to see if they are eligible to attest at a given block height, using a mechanism such as a VRF.

• If an attestor is eligible, it summarizes the progress of the source chain height from the last finalized attestation on Creditcoin to the current height (say h) based on their view. All eligible attestors for that block height sign their attestation and submit it to Creditcoin as their "vote" for the source chain at height h.

• Creditcoin validators verify the eligibility of votes received for a given block height. Each signed attestation from an attestor acts as a vote, and valid attestations with the same value (i.e., same digest) are accumulated. Once the accumulated votes for a particular attestation cross the required threshold, that attestation is confirmed and added to on-chain storage.

Attestation Diagram