Proving World Chain: Scaling ZK to All Humans

Succinct and World Foundation have partnered on a validity proof experiment — a first step to proving every transaction on World Chain. With OP Succinct, even the largest rollups can experience the magic of ZK. Moreover, teams can expect state-of-the-art performance, pricing, and reliability from the decentralized Succinct Prover Network.

World Chain is building the first human-centered blockchain. This improves access to the digital economy by empowering real people instead of MEV bots. ZK proofs are central to this mission, and World has been an early adopter. World’s proof of human protocol, World ID, uses ZK proofs to allow people to prove their unique humanness online — securely and anonymously.

In Q4 of last year, World Foundation began to investigate ZK proofs as a core part of the L1 settlement and decentralization roadmap. After discovering OP Succinct, World Foundation paid Succinct to prove World Chain’s mainnet for 7 days. This bold experiment had one goal: demonstrate the viability of validity proofs for the largest rollups. 

This experiment unlocked exciting options for World Chain's future architecture:

• Fast finality — By slashing finality times from 7 days to 1 hour or less, World Chain can improve key UX like withdrawals by 100x. This helps them get to parity vs. Web2/fintech user journeys, which is critical to serving their customers in emerging markets.
• Stage-1 decentralization — By adopting validity proofs, smart contract governance becomes even easier on World Chain, which in turn improves security, integrity, and decentralization. In a world with growing privacy and sovereignty concerns, this is increasingly important.
• A future-proof proof system — Because OP Succinct is built on SP1, the world’s fastest and most production-ready zkVM, validity proofs are economically viable (i.e., $0.005 per transaction or less, depending on configuration). Costs will continue to drop in each major release (see: SP1 Hypercube), and we are making SP1 more feature rich with tools like two-factor authentication. 

With this experiment, World Foundation has continued their thought leadership in ZK. If your team wants to follow in their footsteps, please reach out to us anytime! 

OP Succinct is World Chain’s path to full ZK

Proving World Chain is no easy feat. 

The chain is designed to operate at scale, with unique primitives like free gas and priority blockspace for humans. These features make World Chain a compelling destination for both users and builders: the chain is home to a thriving ecosystem with almost 5 million MAUs and $475M+ TVL. Much of this growth is in emerging markets like Africa and Southeast Asia, where crypto-native products like stablecoins are growing the fastest.

As a result, World Chain is now one of the largest OP Stack chains, operating at over 8 MGas/s in June. In recent days, it only trails OP Mainnet and Base in gas consumption. Given World’s trajectory, chain activity will only increase in the future.

Previously, upgrading an optimistic rollup to validity proofs would have been difficult as the OP Stack is not directly compatible with most ZK stacks. OP Succinct, by contrast, fully embraces the modularity of Optimism’s design. To make this possible, we worked with OP Labs to synthesize two key technologies: Kona, a Rust implementation of the OP Stack rollup state transition function (STF), and SP1, our state-of-the-art zkVM that verifies any Rust program.  

The resulting solution is incredibly simple and does not touch core components of the OP Stack like the sequencer, batcher, op-node, or op-geth. Rollups just need to:

1. Run a single Forge script to deploy a smart contract that is responsible for verifying proofs of the state transition function and keeping track of the latest verified state root.
2. Run a single Rust command to spin up a lightweight proposer service that monitors the tip of your chain and requests proofs from the Succinct Prover Network.

But proof lies in practice, not theory. 

World Foundation asked us to demonstrate the end-to-end capabilities of OP Succinct in production by running a parallel bridge contract for World Chain’s mainnet. This required serious infrastructure investments. In particular, we:

• Greatly improved our proving systems. Proving World Chain required over 800 GPUs operating at nearly 400 MHz of throughput. To meet this demand, we built more efficient state management and networking, which allowed us to reliably autoscale up and down as activity fluctuated.
• Enhanced our monitoring and alerting systems. We developed a new metric called “prover gas” to more accurately estimate proof generation costs, which gives us more visibility into the computational cost structure. We also established more robust playbooks for responding to production incidents. 

We also battle tested our open-source dependencies at scale. We discovered several bugs in Kona while running World Chain, and we worked with OP Labs to fix and merge (#1, #2) those issues in a subsequent release. In the process, we also helped Optimism improve their testing framework. Fundamentally, we view this as a win for the overall health and security of the open-source community. 

After the Kona fixes, we delivered E2E proving for 7 days with no interruptions: the parallel bridge contract is available here. During this process, we achieved a cost structure of $0.0102 per transaction and $0.0184 per MGas. Going forward, we expect another 2-3x cost reduction from proof system improvements and similar reductions from investments in on-prem compute.

Every rollup should follow in World Chain’s footsteps

ZK rollups are the endgame for Ethereum’s scaling roadmap, and Succinct has the only production-ready solution for the OP Stack. 

We are excited to continue working with World Foundation as they refine their ZK strategy and scale World Chain to tens of millions of users. We are grateful for their ongoing commitment to ZK technology and their continued leadership in our industry.

We look forward to running a similar experiment after SP1 Hypercube is in production. We expect significant cost and latency improvements, making OP Succinct accessible to rollups of every size.

If your team wants to join the movement, please reach out to us here. If you use a rollup-as-a-service provider, you can also ask them to contact us.