Casper Friendly Finality Gadget (CFFG)
Casper Friendly Finality Gadget (CFFG) is a hybrid Proof-of-Work (PoW) and Proof-of-Stake (PoS) protocol that facilitates Ethereum’s transition to a PoS system. With CFFG, Ethereum’s blocks will still be mined using PoW, and approximately 2% of blocks will be finalized by network validators through this system. CFFG is part of Ethereum’s multi-step transition towards a complete PoS system, with the final version expected to resemble Casper Correct by Construction (CBC) to a greater extent.