What Is a “Finality Gadget” and How Does It Differ from Checkpointing?
A finality gadget is a mechanism that is used to provide absolute finality to a blockchain's blocks, meaning that they cannot be reverted. It differs from checkpointing in that it is an integral part of the blockchain's consensus mechanism, rather than a separate process that is anchored to another chain.
A finality gadget typically involves a supermajority of validators signing off on a block, which provides a much stronger guarantee of finality than a checkpoint. However, finality gadgets can be more complex to implement and can introduce additional overhead to the consensus process.
Glossar
Finality Gadget
Component ⎊ Finality Gadget refers to the specific module or sub-protocol within a larger consensus mechanism responsible for aggregating validator attestations and producing the cryptographic proof that confirms the irreversible ordering of blocks.
Absolute Finality
Settlement ⎊ Absolute finality, within cryptocurrency systems, denotes the irreversible confirmation of a transaction on a distributed ledger, eliminating the possibility of reversal or alteration.
Checkpointing
Finality ⎊ Checkpointing is a mechanism in Proof-of-Stake protocols designed to establish transaction finality by creating irreversible points in the blockchain history.