Casper Friendly Finality Gadget (CFFG)

Casper Friendly Finality Gadget (CFFG) is a proof-of-work (PoW)/proof-of-stake (PoS) hybrid protocol that allows Ethereum to transition to a PoS system. Ethereum’s blocks will still be mined using PoW through the CFFG, and only about 2% of blocks will be finalized by network validators using this system. CFFG is part of Ethereum’s multi-step transition to a full PoS system, and the final version of Ethereum will most likely run on something more akin to Casper Correct by Construction (CBC).