Casper the Friendly Finality Gadget (FFG)

Friendly Finality Gadget (FFG), hybrid PoW/PoS. FFG is a Proof of Stake algorithm implementing stake slashing for bad behavior like chain halts and censorship. Foreseen for Ethereum 2.0


  • validators stake a portion of their Ethers as stake.

  • validators start validating the blocks. when they discover a block which they think can be added to the chain, they will validate it by placing a bet on it.

  • If the block gets appended, he validators will get a reward proportionate to their bets.

  • Malicious validator acts trying to do a “nothing at stake”, the will immediately be punished, and all of their stake is going to get slashed.


  • all Pros of Proof of stake

  • punish validator trying to do a “nothing at stake” attack,

  • punishing miners who go offline, unintentionally or not,

Used in


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