Overview
Casper refers to the specific Proof of Stake (PoS) implementation developed for Ethereum. There were two main versions: Casper FFG (Friendly Finality Gadget) and Casper CBC (Correct-by-Construction).
Key Concepts
- Finality: Casper introduces a mechanism to 'finalize' blocks, meaning they can never be reverted. This is achieved through a voting process where validators risk their stake.
- Slashing: If a validator signs two conflicting versions of history, Casper allows the network to 'slash' (take away) their staked ETH.
- Incentives: Validators are rewarded for being online and voting correctly, and penalized for being offline or acting maliciously.
Result
Casper FFG was eventually integrated into the Beacon Chain, which now serves as the consensus layer for Ethereum.