Required Block Confirmations
Block confirmation requirements for attestations on each chain
Before signing an attestation for a source chain event, Circle waits for a specified number of on-chain block confirmations to pass to determine finality. The following table displays the average time it takes for an attestation to become available after a source chain event, which includes the ~20 seconds it takes for the attestation service to observe and sign the source chain event.
Note: These values are subject to change.
Mainnet
| Source Chain | Number of Blocks | Average Time |
|---|---|---|
| Ethereum | ~65* | ~13 minutes |
| Avalanche | 1 | ~20 seconds |
| OP Mainnet | ~65 ETH blocks* | ~13 minutes |
| Arbitrum | ~65 ETH blocks* | ~13 minutes |
| Noble | 1 | ~20 seconds |
| Base | ~65 ETH blocks* | ~13 minutes |
| Polygon PoS | ~200* | ~8 minutes |
| Solana | 32 | ~25 seconds |
Testnet
| Source Chain | Number of Blocks | Average Time |
|---|---|---|
| Ethereum Sepolia | 5 | ~1 minute |
| Avalanche Fuji | 1 | ~20 seconds |
| OP Sepolia | 5 | ~20 seconds |
| Arbitrum Sepolia | 5 | ~20 seconds |
| Noble Testnet | 1 | ~20 seconds |
| Base Sepolia | 5 | ~20 seconds |
| Polygon PoS Amoy | 1 | ~20 seconds |
| Solana Devnet | 32 | ~25 seconds |
Block confirmations for L2s to Ethereum
Arbitrum, Base, and OP Mainnet are L2 blockchains that publish transaction data to their L1 blockchain, Ethereum. Before attesting to CCTP messages in an Ethereum block, Circle waits for the Ethereum block to finalize, which requires at least 65 block confirmations.
Block confirmations for Polygon PoS
We have currently set our time-to-attestation at 200 blocks for events on Polygon PoS mainnet. Deterministic finality (PIP-11) was rolled out on Polygon PoS mainnet in 2023, and we may reduce our time-to-attestation time as we observe PIP-11's performance.
Updated about 1 month ago