Slashing on Ethereum
Slashing is the irreversible punishment that decreases a percentage of a validator’s current stake over time and forcibly ejects them from the network. It is the punishment given to validators who violate any of these three offences:- Double Proposal - proposing validator signs two different blocks for the same slot
- Surround Vote - attesting validator signs a Casper FFG attestation (source
s
and targett
) that “surrounds” another one, which contradicts what a validator said was finalized in a previous attestation
- Double Vote - attesting validator signs two different attestations with the Casper FFG target
Mechanics of Slashing
Slashing requires a whistle-blowing validator that monitors and reports on any of the three offenses listed. This whistleblower sends a message to the network outlining the offense. After which, the proposing validator includes this message in their slot. They then get awarded the offending validator’s balance divided by 65,536 (~0.00048 ETH if the balance is 32 ETH). The reward is small since this is not meant to be a for-profit activity; rewarding reports as such would encourage false positive reports/spam. As for the whistleblower, they get the offending validator’s balance divided by 4096 (~0.00781 ETH if the balance is 32 ETH).Slashing Penalties
At a high enough level, so far we have observed slashed validators be subject to the following levels of principal loss across Beacon Chain eras:Upgrade era | Principal loss on slashing (approx.) |
---|---|
Phase 0 | 0.25 ETH |
Altair | 0.5 ETH |
Bellatrix | 1 ETH |
Electra | ~0.00781 ETH (32 ETH validator) |
- Pre-Altair: Slashed Validator’s Effective Balance * 1/32
- Post-Altair: Slashed Validator’s Effective Balance * 1/64
- Post-Merge: Slashed Validator’s Effective Balance * 1/32
- Post-Electra: Slashed Validator’s Effective Balance * 1/4096
- Pre-Altair: 3 * Base Reward * 32 (per epoch)
- Post-Altair: 40/64 * Base Reward * 32 (per epoch)
- Post-Merge: 40/64 * Base Reward * 32 (per epoch)
- Post-Electra: 40/64 * Base Reward * Effective Balance (per epoch)
- This penalty is higher if an inactivity leak is activated in the network.
- Takes into consideration the number of validators slashed during the period 18 days before the offending validator was slashed and 18 days after (aka 36 days before this halfway point)
- Maximum amount can be as high as the slashed validator’s total effective balance