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✅Permissionless Proof System

Almost complete (Still needs a trusted guardian role)

Previously, we explored OP Stacks' expansion to Superchain, highlighting the Chain Factory. This innovative function allows for the creation of unlimited OP chains using only the bedrock bridge and SystemConfigs on Layer 1.

🚨 But, like all Optimistic rollups, Withdrawal Claims are a major issue, particularly with invalid state roots from malicious block proposers.

Trust Issues: Befor the upgrade users needed to rely on block proposers to accurately submit the Layer 1 state root on all OP Chains. The risks?

  1. Stolen Funds: If an invalid state root is submitted.

  2. MEV Extraction: If operators exploit their position to front-run transactions.

  3. Frozen Funds: If the centralized validator fails.

Optimism's Leap Towards Decentralization:

The Fault Proof Upgrade ⚙️

Optimism is taking a giant stride towards decentralization with its latest upgrade: the Fault Proof system. It serves as a fundamental shift in how the Layer 2 network operates and interacts with Ethereum.

The Fault Proof Game 🕹️

Here's how the new system works now:

  1. Anyone can propose an L2 state root (with a financial stake)

  2. Others can challenge this proposal (also with a stake)

  3. A back-and-forth proving process ensues

  4. The game resolves, determining the valid state

However this bicycle still has some safety wheels

The Guardian's Watch 🛡️

While this system is more decentralized, it's not without safeguards:

  • A Guardian role can pause the system in emergencies

  • Delayed WETH contracts hold bonds, allowing for corrections

  • Off-chain monitoring ensures proposed roots align with the correct state

This upgrade lays the groundwork for tomorrow:

  • A smart contract framework for multi-proof systems

  • Easier addition of new proof systems in the future

  • Moving towards Stage 2 decentralization in the OP Stack

Technicalities (For the Curious)

  • New contracts deployed: DisputeGameFactory, FaultDisputeGame, and more

  • OptimismPortal upgrade for new withdrawal proving process

  • SystemConfig updates for dispute game integration

Let's dive deeper into the new contracts that form the backbone of this upgrade:

DisputeGameFactory 🏭

  • Purpose: Creates and manages dispute games

  • Key feature: Acts as the new source of proposed output roots

  • Address: 0xe5965Ab5962eDc7477C8520243A95517CD252fA9

Think of this as the grand arena where all disputes are born and settled. It's the factory that produces the games that keep Optimism honest!

FaultDisputeGame 🎮

  • Purpose: Implements the actual dispute game logic

  • Key feature: Uses permissionless, interactive bi-section of chain state

  • Address: 0x4146DF64D83acB0DcB0c1a4884a16f090165e122

PermissionedFaultDisputeGame 🔐

  • Purpose: A restricted version of FaultDisputeGame

  • Key feature: Limits participation to privileged roles

  • Use case: Serves as a fallback in case of emergencies

AnchorStateRegistry ⚓

  • Purpose: Stores the latest "anchor" state for each game type

  • Key feature: Allows games to start from a more recent state

  • Benefit: Reduces required off-chain computation

Imagine this as a checkpoint system in a video game - you don't always have to start from the very beginning!

DelayedWETH ⏳

  • Purpose: Extends WETH9 with delayed withdrawals

  • Key feature: Introduces a time delay for bond withdrawals

  • Safety measure: Allows for bond reallocation if bugs are found

PreimageOracle 🔮

  • Purpose: Stores validated pre-images retrievable by hash

  • Use: Supports the derivation process in fault proofs

MIPS 💻

  • Purpose: Implements the Cannon MIPS VM

  • Key feature: Executes single MIPS CPU instructions on-chain

This is like having a tiny computer within the blockchain, capable of running one instruction at a time to verify complex computations.

What This Means for Users

  1. Pending withdrawals will need to be re-proven (but don't worry, it's for the better!)

  2. Slightly longer withdrawal times in some cases (up to 16 days in extreme scenarios)

  3. A more robust, decentralized network overall

This upgrade is like replacing the foundations of a bridge while cars are still crossing. It's complex, but necessary for a stronger, more resilient Optimism.

Remember, this isn't just a technical upgrade – it's a step towards a more open, trustless, and powerful Layer 2 ecosystem. It's not just optimizing Optimism; it's reimagining what blockchain infrastructure can be!

Devsources

Here you get quick access to the most important pieces of docs and articles, curated for devs.

This bookmark takes you to the more technical talk and the discourse around this upgrade:

PreviousChain FactoriesNextConfigurable Sequencer per OP Chain.

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