LibraryConsensus2017Design paperCorpus record
The Sleepy Model of Consensus
Sleepy Consensus. Rafael Pass and Elaine Shi.
Only awake nodes participate. A public randomness beacon picks a leader from the awake stake. Sleeping nodes do not have to be online to keep their stake safe.
A reading of the public document. Not a copy of it, and not a claim about a later network that reused the name.
A staking design that punishes everyone who misses a slot has refused this model. Ask what an offline holder must do.
The five-minute read
The defect
Proof of stake had been stuck on the nothing-at-stake and costless-simulation problems, and on the fact that most holders are offline.
The rule
Only awake nodes participate. A public randomness beacon picks a leader from the awake stake. Sleeping nodes do not have to be online to keep their stake safe.
How it is put together
Sleepy means offline, not Byzantine. The adversary cannot grind the leader lottery after seeing the future. A node that wakes up can tell which chain is the one honest awake nodes built.
Where the claim stops
The paper is not Ouroboros and not Casper.
One action, walked through
- Time is divided into slots.
- A slot leader extends the chain it considers heaviest.
- A node that was asleep downloads and applies the same fork-choice rule.
- Who is assumed awake?
The argument, unpacked
Why it is still on the desk
A staking design that punishes everyone who misses a slot has refused this model. Ask what an offline holder must do.
After the text
Ouroboros Praos and later sleepy-style protocols share the awake-majority idea. Ethereum's inactivity leak is a different answer to offline stake.
What has to be true
- The paper is not Ouroboros and not Casper.
- It does not solve light-client data availability by itself.
- Awake majority is the security assumption. Count it.
What happened after the paper
Ouroboros Praos and later sleepy-style protocols share the awake-majority idea. Ethereum's inactivity leak is a different answer to offline stake.
What to check before you use the idea
- Who is assumed awake?
- Can the leader lottery be ground?
- What does a node that slept for a month accept as the chain?
Terms
- Sleepy
- Honest but offline. Not an attacker.
- Awake majority
- Most of the stake that is online follows the protocol.
The problem the paper names
Proof of stake had been stuck on the nothing-at-stake and costless-simulation problems, and on the fact that most holders are offline.
What the design proposes
- Sleepy means offline, not Byzantine.
- The adversary cannot grind the leader lottery after seeing the future.
- A node that wakes up can tell which chain is the one honest awake nodes built.
How the mechanism is specified
- Time is divided into slots.
- A slot leader extends the chain it considers heaviest.
- A node that was asleep downloads and applies the same fork-choice rule.
What this page does not treat as proven
- The paper is not Ouroboros and not Casper.
- It does not solve light-client data availability by itself.
- Awake majority is the security assumption. Count it.
Why a venture studio still reads it
A staking design that punishes everyone who misses a slot has refused this model. Ask what an offline holder must do.
This is Blockchain Lab's reading of a public design paper. It is not the paper, not a copy of it, and not an offer of tokens, equity, custody or a partnership. Later network behaviour can diverge from the text. Nothing here is investment, legal or technical advice.
Research status: Design paper. Last reviewed: 1 October 2026. This is a reading of a public paper, not investment, legal or security advice.