How Does the “Nothing-at-Stake” Problem Relate to PoS and How Is It Mitigated?
The "nothing-at-stake" problem is a historical concern in PoS where validators have no financial incentive to choose only one chain during a fork. Since it costs them nothing to validate on multiple chains, they might do so, hindering consensus.
Ethereum mitigates this by penalizing (slashing) validators who attest to multiple conflicting blocks. This creates a financial cost for dishonest behavior.
This mechanism ensures validators commit to a single chain.
Glossar
Pos
Mechanism ⎊ Pos, within cryptocurrency derivatives, denotes a documented state of an open position, typically reflecting the directional exposure ⎊ long or short ⎊ and associated notional value.
Ethereum
Architecture ⎊ Ethereum represents a decentralized, open-source blockchain system fundamentally altering programmable money and contract execution.