Proof of stake
Proof of stake is a way for a blockchain to choose who adds the next block based on crypto they have locked up as a stake. Ethereum switched to it from proof of work in September 2022. Validators who try to cheat can lose some or all of that stake.
How does proof of stake choose who adds a block?
NIST's summary: the more stake a participant has put in, the more likely they are to be chosen to publish the next block. Ethereum's version works in time slots. According to ethereum.org, one validator is picked at random to propose a block in each slot, and a randomly chosen committee of validators votes on whether that block is valid.
To run a validator of your own on Ethereum, ethereum.org says you must deposit 32 ETH into a deposit contract and run three separate pieces of software.
How is proof of stake different from proof of work?
| Proof of work | Proof of stake | |
|---|---|---|
| What earns the right to publish | Solving a costly puzzle | Having crypto staked |
| What an attacker risks | Hardware and electricity spent | The stake itself |
| Energy use | High, per NIST | Far lower |
On energy, ethereum.org cites estimates from CCRI that the switch cut Ethereum's annualised electricity consumption by more than 99.988%. Compare our page on proof of work.
What happens when a validator breaks the rules?
Ethereum.org defines proof of stake as proof that validators have put something of value into the network that can be destroyed if they act dishonestly. Example: a validator proposes two different blocks for one slot, or sends conflicting votes. Some or all of its staked ETH can then be destroyed. This penalty is known as slashing.
What are the risks and criticisms of proof of stake?
- Concentration. NIST notes that nothing stops stakeholders pooling their stake into a centralised power.
- Less track record. Ethereum.org itself says proof of stake is younger and less battle-tested than proof of work.
- Custody when staking through a platform. Staking pools let people take part without 32 ETH, but if a platform holds your keys, you take on the custody risks the SEC describes.
Frequently asked questions
Do I need 32 ETH to take part?
To run your own Ethereum validator, ethereum.org says yes. Staking pools allow smaller amounts, but you then depend on the pool and whoever controls the keys.
Is proof of stake safer than proof of work?
They carry different risks. Proof of stake uses far less energy, but ethereum.org calls it less battle-tested, and NIST flags the risk of stake concentrating in a few hands.
Sources
- NIST IR 8202, Blockchain Technology Overview (2018) — nvlpubs.nist.gov (accessed 2026-10-02)
- ethereum.org (Ethereum Foundation), Proof-of-stake (PoS) — ethereum.org (accessed 2026-10-02)
- ethereum.org (Ethereum Foundation), Ethereum energy consumption — ethereum.org (accessed 2026-10-02)
- SEC, Crypto Asset Custody Basics for Retail Investors – Investor Bulletin (Dec 2025) — investor.gov (accessed 2026-10-02)