LibraryConsensus1982Design paperCorpus record
The Byzantine Generals Problem
Byzantine Generals. Leslie Lamport, Robert Shostak and Marshall Pease.
With oral messages, more than two thirds must be loyal. With signed messages, any number of traitors can be tolerated if a loyal commander is heard.
A reading of the public document. Not a copy of it, and not a claim about a later network that reused the name.
When a pitch says Byzantine, ask whether messages are authenticated and what fraction of the set can equivocate.
The five-minute read
The defect
Loyal generals must agree on one plan even when some generals send conflicting orders.
The rule
With oral messages, more than two thirds must be loyal. With signed messages, any number of traitors can be tolerated if a loyal commander is heard.
How it is put together
Oral messages can be forged by the receiver. Signed messages cannot, if signatures hold. The bound is about agreement, not about throughput.
Where the claim stops
The oral-message bound does not apply to a chain with a known stake weight.
One action, walked through
- A commander sends an order. Lieutenants exchange what they heard.
- Each lieutenant decides on a value that all loyal lieutenants share.
- If the commander is loyal, that value is the commander's order.
- Are messages signed?
The argument, unpacked
Why it is still on the desk
When a pitch says Byzantine, ask whether messages are authenticated and what fraction of the set can equivocate.
After the text
PBFT, HotStuff and Tendermint are later systems under authenticated messages and partial synchrony. The 1982 paper is the problem statement.
What has to be true
- The oral-message bound does not apply to a chain with a known stake weight.
- Signatures change the bound. Quoting the one-third rule without saying which model is a mistake.
- The paper is not a networking protocol.
What happened after the paper
PBFT, HotStuff and Tendermint are later systems under authenticated messages and partial synchrony. The 1982 paper is the problem statement.
What to check before you use the idea
- Are messages signed?
- Is the bound one third or something weaker?
- Does a loyal leader's value have to be the one that commits?
Terms
- Oral message
- A message the receiver can alter when forwarding.
- Signed message
- A message whose author a traitor cannot forge.
The problem the paper names
Loyal generals must agree on one plan even when some generals send conflicting orders.
What the design proposes
- Oral messages can be forged by the receiver.
- Signed messages cannot, if signatures hold.
- The bound is about agreement, not about throughput.
How the mechanism is specified
- A commander sends an order. Lieutenants exchange what they heard.
- Each lieutenant decides on a value that all loyal lieutenants share.
- If the commander is loyal, that value is the commander's order.
What this page does not treat as proven
- The oral-message bound does not apply to a chain with a known stake weight.
- Signatures change the bound. Quoting the one-third rule without saying which model is a mistake.
- The paper is not a networking protocol.
Why a venture studio still reads it
When a pitch says Byzantine, ask whether messages are authenticated and what fraction of the set can equivocate.
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.