Ethereum can impose a slashing loss up to a validator’s full effective balance when a large amount of network stake is slashed within 36 days, making key management an operational concern.
Ethereum treats three types of conflicting signatures as slashable: proposing multiple blocks for one slot, supporting different messages with the same target epoch, or sending attestations whose source and target epochs form a nested pattern. Routine missed duties follow separate rules.
Ethereum’s proof-of-stake rewards and penalties documentation sets the initial deduction at 0.0078125 ETH for a validator with 32 Ether (ETH) in effective balance. Once slashed, it must exit the validator set. The same documentation specifies a correlation penalty on Day 18 of the 36-day period. Its size depends on how much stake is slashed across the network during that window; a larger total can increase the penalty. If that amount is high enough, the loss can consume the validator’s entire effective balance.
A skipped block proposal is not slashable on its own, though missed attestations may reduce rewards or bring participation penalties. If Ethereum goes more than four epochs without finality, its inactivity leak gradually reduces the stake of inactive validators. That leak is a separate mechanism from slashing.
Key-handling errors can produce the conflicting signatures that trigger slashing. Using one validator key across clients running at the same time can create conflicts, as can migrating a key without its earlier signing records. EIP-3076 defines a format for moving slashing-protection records between clients. Those records let clients check signature history, but do not prevent every operational failure.
Solo stakers face protocol penalties directly. In delegated, pooled or exchange staking, a service operates the validator; its terms determine whether a loss is passed on to customers.
