Skip to content
Blockchain LabBlockchain LabTHE VENTURE STUDIO

LibraryScaling2023Design paperCorpus record

The Fault Proof System

Optimism Cannon. Optimism.

A dispute walks a single instruction of a state transition on a parent chain, so anyone who can post a bond can force the on-chain step that decides a bad proposal.

A reading of the public document. Not a copy of it, and not a claim about a later network that reused the name.

Ask who may challenge, how long the window is, and where the transaction data sits. Those three decide whether the spec is in force.
Evidence
Primary paper
Re-measured
No
Assumptions
3
Records linked
3

Code

Source, repository, and what is actually hosted

  • OP fault-proof spechttps://specs.optimism.io/fault-proof/index.html
  • The source URL is not a GitHub repository. No code remote is invented.
  • Full text is not mirrored. Public availability is not a licence to copy the file onto this site.
  • Add to a reading list

01 Claim ledger

What the paper is allowed to say

Each row is a sentence already in the study. The status is the same on every row: a model claim, not a live measurement.

  1. Claim 01 · Paper model

    The defect

    An optimistic rollup that can only be challenged by a permissioned set is a multisig with extra steps.

  2. Claim 02 · Paper model

    The rule

    A dispute walks a single instruction of a state transition on a parent chain, so anyone who can post a bond can force the on-chain step that decides a bad proposal.

  3. Claim 03 · Paper model

    How it is put together

    The proposal is innocent until a dispute says otherwise. The game narrows to one instruction. The parent chain is the referee, not the executor of every transaction.

  4. Claim 04 · Paper model

    Where the claim stops

    The spec is the mechanism. A live chain may still gate who may propose.

02 Three cuts

Observation, model, falsifier

A desk does not stop at the summary. Each claim is cut three ways, using only this study's own assumptions and checks. Nothing here is a new figure.

  1. 01 The defect

    Observation

    What the study says

    An optimistic rollup that can only be challenged by a permissioned set is a multisig with extra steps.

    Model

    What has to hold

    The spec is the mechanism. A live chain may still gate who may propose.

    Falsifier

    What would retire it

    Who may open a dispute?

  2. 02 The rule

    Observation

    What the study says

    A dispute walks a single instruction of a state transition on a parent chain, so anyone who can post a bond can force the on-chain step that decides a bad proposal.

    Model

    What has to hold

    The spec is the mechanism. A live chain may still gate who may propose.

    Falsifier

    What would retire it

    Who may open a dispute?

  3. 03 How it is put together

    Observation

    What the study says

    The proposal is innocent until a dispute says otherwise. The game narrows to one instruction. The parent chain is the referee, not the executor of every transaction.

    Model

    What has to hold

    The spec is the mechanism. A live chain may still gate who may propose.

    Falsifier

    What would retire it

    Who may open a dispute?

  4. 04 Where the claim stops

    Observation

    What the study says

    The spec is the mechanism. A live chain may still gate who may propose.

    Model

    What has to hold

    The spec is the mechanism. A live chain may still gate who may propose.

    Falsifier

    What would retire it

    Where is the data the instruction reads?

03 Sequence

One action, as an operating tape

  1. 01A proposer posts a state root.
  2. 02A challenger posts a disagreement.
  3. 03Bisection continues until one instruction is checked on the parent.
  4. 04Who may open a dispute?

04 Load-bearing

The argument, and where a pitch drops it

  1. Why it is still on the desk

    The cut

    Ask who may challenge, how long the window is, and where the transaction data sits. Those three decide whether the spec is in force.

    Why it carries weight

    If this cut is skipped, the paper's name is being used without the mechanism that makes the name mean anything.

    Where it is dropped

    A later client, parameter or reward formula is a different object from this paragraph.

  2. After the text

    The cut

    OP mainnet moved toward permissionless fault proofs after running with a security council. The spec and the deployment date are different citations.

    Why it carries weight

    If this cut is skipped, the paper's name is being used without the mechanism that makes the name mean anything.

    Where it is dropped

    A fault proof does not make data available. If the data was withheld, the bisection may have nothing to read.

05 Register

What has to be true

  • Model · Not re-measured

    The spec is the mechanism. A live chain may still gate who may propose.

  • Cryptography · Not re-measured

    A fault proof does not make data available. If the data was withheld, the bisection may have nothing to read.

  • Cryptography · Not re-measured

    This is not Arbitrum's protocol and not a ZK proof.

06 Divergence

What happened after the paper

OP mainnet moved toward permissionless fault proofs after running with a security council. The spec and the deployment date are different citations.

A later client, parameter set, or reward formula is a different object. Cite this paper for the mechanism. Cite a primary release for the network. This desk has not re-run the proof.

07 Pre-mortem

What to check before you use the idea

  4. 0 of 3 marked on this browser. A mark is a reading note, not a pass, a rating, or a recommendation.

08 Anatomy

The paper, in the order a builder needs

The problem it names

An optimistic rollup that can only be challenged by a permissioned set is a multisig with extra steps.

What the design proposes

  • The proposal is innocent until a dispute says otherwise.
  • The game narrows to one instruction.
  • The parent chain is the referee, not the executor of every transaction.

How the mechanism is specified

  • A proposer posts a state root.
  • A challenger posts a disagreement.
  • Bisection continues until one instruction is checked on the parent.

What this page does not treat as proven

  • The spec is the mechanism. A live chain may still gate who may propose.
  • A fault proof does not make data available. If the data was withheld, the bisection may have nothing to read.
  • This is not Arbitrum's protocol and not a ZK proof.

Why the desk still reads it

Ask who may challenge, how long the window is, and where the transaction data sits. Those three decide whether the spec is in force.

09 Lexicon

Terms, opened into the record

Bisection
Cutting a disputed computation in half until one step remains.
State root
A commitment to the rollup state a proposer claims.

10 Repository

Every linked record on this page

Underlined words open a page that already exists: a concept, a protocol profile, a failure record, or another paper. If a word is not underlined, this desk does not have a record for it.

Protocols

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.