What is proof of stake, and what does a validator put at risk?
Proof of stake is a way of proving that a validator has put something of value into the network that can be destroyed if they act dishonestly. On Ethereum participation requires depositing 32 ETH, and both the block proposer and the voting committee are chosen at random. We set out what the mechanism claims and what it does not.
In short
Ethereum's own definition:
"Proof-of-stake is a way to prove that validators have put something of value into the network that can be destroyed if they act dishonestly."
The weight of the sentence sits at the end: can be destroyed. The system does not rest on a validator's good intentions but on their having something to lose.
The cost of taking part
Both the deposit and the software requirement are stated:
"To participate as a validator, a user must deposit 32 ETH into the deposit contract and run three separate pieces of software."
The two conditions matter together. Depositing is not enough; the validator has to actually be running on the network.
Who proposes a block is drawn, not chosen
In each slot one validator is selected at random as block proposer. Validity is not decided by a single party:
"a committee of validators is randomly chosen, whose votes are used to determine the validity of the block being proposed."
Committees divide the validator set so that every active validator attests in every epoch, though not in every slot.
The randomness is not decoration: a party who knew the order in advance could build an attack around it.
Finality is a threshold
A transaction becomes irreversible once reversing it would cost enough. In the source's terms a transaction is final when it is part of a block that cannot change without a large amount of ETH being burned, and that requires votes representing at least two thirds of the total staked ETH.
So "confirmed" and "finalised" are not the same thing.
Dishonest behaviour is defined
The source names two behaviours: proposing multiple blocks in one slot, and submitting contradictory attestations. The severity depends on whether the misbehaviour was isolated or coordinated, and can reach destruction of the entire stake.
How the penalty works is covered separately in slashing.
Risks
Biggest uncertainty This piece describes Ethereum; other networks implement proof of stake differently and were not examined.
- A stake is a deterrent, not proof of honesty. That a validator deposited 32 ETH does not show they behaved correctly; it shows what they lose if they did not.
- Confirmed and finalised differ. A transaction may be in a block and not yet final.
- Delegated participation is a separate matter. Pools for those without 32 ETH were not examined here and carry their own risks.
- This piece describes Ethereum. Other networks implement proof of stake differently.
What was not examined is listed in the data status above.
Sources
This article rests on the sources below. Whether each has a permanent copy is stated next to it.
- #1
Primary source for the definition, the 32 ETH requirement, random selection and the finality threshold: the ethereum.org documentation.
ethereum.org· no permanent copy· no screenshot
Evidence chain: 1 sources
Tweets get deleted, sites go down. Below is whether a durable copy exists for each source.
Sources (1)
- #1
Primary source for the definition, the 32 ETH requirement, random selection and the finality threshold: the ethereum.org documentation.
“Proof-of-stake is a way to prove that validators have put something of value into the network that can be destroyed if they act dishonestly.”
ethereum.org/developers/docs/consensus-mechanisms/pos/- no durable copy: if the source disappears, this claim loses its basis
- no screenshot captured
Correction history
Articles are never deleted, only corrected. Every change appears here.
- Version 1 ·
Section