How blockchain confirmations secure transactions and ensure finality across Circle products.
Blockchain confirmations secure transactions and ensure finality on a
blockchain. When you build on Circle’s platform, understanding confirmations
helps you balance speed with the risk of blockchain reorganizations (reorgs).
When you submit a transaction to a blockchain, it starts in a pending state. The
network must include it in a block and validate it before it counts as
confirmed. Each new block added after that makes the transaction harder to
reverse.A confirmation number is the number of blocks that must follow a
transaction’s block before it is final. Once the confirmation number is reached,
the transaction can’t be reversed.
Without enough confirmations, transactions are at risk of reorgs. A reorg
happens when validators discard recent blocks and replace them with new ones,
rewriting part of the blockchain’s history. This can reverse transactions that
appeared settled.Each extra confirmation makes a reorg less likely. Because blockchains differ in
design, block times, and consensus, the number of confirmations needed varies by
blockchain.
