The Citrea Recap – March

The Citrea Recap – March

Welcome to The Citrea Recap, the only newsletter covering everything Citrea. 

If this is your first time, welcome! Be sure to sign up for the newsletter to automatically get monthly Citrea alpha! 

Citrea is the first rollup that enhances the capabilities of Bitcoin blockspace with zero-knowledge technology. Citrea’s mission is to build a programmable liquidity layer on top of the most secure and decentralized blockchain, Bitcoin.

Here’s what we’ll be covering today: 

  • Roadmap Details 🛣️
  • Unveiling Clementine 🍊
  • Open-sourcing Core Codebase & BitVM ZK Verifier🔓
  • Citrea & The Bitcoin Halving 🎉
Fun Take: What is Citrea?

Roadmap Details

At the current stage, Citrea is capable of inscribing zk proofs into Bitcoin and reading them back. Citrea can currently handle Groth16 verification in 4B cycles, indicating being able to verify zk proofs efficiently in BitVM. The development is ongoing to reduce the verification cycles further to optimize the bridge implementation. We are also actively researching BitVM 2 for further optimization.

We published our roadmap to bring Bitcoin's First ZK Rollup in early March. Looking ahead, Q2 and Q3 of 2024 will be epic for Citrea. In Q2, we plan to launch Testnet Phase 1 with a feature complete rollup. Q3 will see the launch of Testnet Phase 2, which will include a complete bridge implementation. Our ambitious goal is to conclude 2024 with the launch of Citrea Mainnet Beta.

But we're not stopping there. For 2025 and beyond, we have grand plans for the development of a Multi Sequencer Network, the implementation of the Volition Model, and the introduction of an EVM+ Run Time.

As our roadmap highlights, March was an open-sourcing marathon for Citrea. We will discover what exactly we open-sourced in the upcoming sections. 

Citrea Roadmap

The main squeeze: Citrea's roadmap is unveiled, and open-sourcing of the entire Citrea codebase has occurred. The future is bright!

Unveiling Clementine

This month, we have introduced Clementine, Citrea's BitVM-based trust-minimized two-way peg program.

At its core, Clementine will enable the most secure and trust-minimized two-way peg mechanism on Bitcoin possible today without requiring a soft fork. Clementine’s architecture is implemented around BitVM to enable a secure two-way peg mechanism for Citrea. Citrea’s light client and BitVM ZK Verifier are the cornerstone of Clementine’s architecture. 

So, how does it work? Let's break it down with the example of 1 BTC deposit:

  1. Peg-in: Users lock 1 BTC into a special UTXO that requires signatures from verifiers, the bridge operator, and the user. Once the transaction is finalized on Bitcoin, the user can mint their pegged BTC on Citrea by showing a SPV proof to the smart contract.
  2. Peg-out: To withdraw, users transfer 1 BTC to a smart contract on Citrea, along with a Bitcoin address. The 1 BTC is burned on Citrea, and the Bitcoin address is recorded in the "Withdrawal Merkle Tree." The operator sends 1 BTC to the user’s address after the batch proof including the transaction is finalized on Bitcoin.
Clementine: Citrea's BitVM Based Trust-Minimized Two-Way Peg Program

Citrea, through Clementine, enables the first trust-minimized two-way peg mechanism on Bitcoin. As long as the single verifier in the BitVM setup is honest, Clementine remains secure. This trust-minimized two-way peg is a significant improvement over existing solutions. For a full detailed explanation of how Clementine works, read this blog piece

The main squeeze: Clementine brings the first trust-minimized two-way peg mechanism on Bitcoin, allowing Citrea to fully unlock Bitcoin’s capital and potential.

Open-sourcing Core Codebase & BitVM ZK Verifier

As we said before, March was an open-sourcing marathon for Citrea. Upholding our promise on the roadmap, we completed the open-sourcing of the entire Citrea components, including our core codebase and BitVM ZK Verifier alongside Clementine. 

First up, we're proud to open-source our BitVM ZK (Groth16) Verifier. Developers can now generate a STARK proof using RiscZero, wrap it into a Groth16 proof, and generate its corresponding verifier in the rv32i and BitVM instruction set. While our Groth16 Verifier is still a work in progress, it's an important step towards verifying ZK proofs on Bitcoin.

We have also open-sourced the core codebase of Citrea, built on the Sovereign SDK. This includes the full node, sequencer, and prover. We've made some Bitcoin-specific changes to the SDK, which we plan to upstream by merging our efforts and to create the most scalable rollup for Bitcoin.

With our core codebase nearing its testnet release, we're inviting contributions from developers across the entire stack. If you're interested in joining our team full-time, check out our job board

Last but not least, we're extremely proud to open-source Clementine, our trust-minimized two-way peg program. To learn more about how it works, read our detailed article. You can also check out the work-in-progress implementation of Clementine in our repo.

The main squeeze: Citrea has open-sourced key components of its codebase, including the BitVM ZK Verifier, core codebase, and Clementine. Building for Bitcoin, on Bitcoin.

Citrea's Halving Campaign

We at Citrea couldn't be more excited for the Halving! To celebrate this historical moment, we have launched the Halving Campaign, a two-part initiative designed to test our community’s knowledge, showcase creativity, and reward our community for their contributions.

First up, we've got a galxe multiple-choice quiz that challenges your understanding of the Halving, Citrea, and their significance. If you've been paying attention, this should be a piece of cake! 

We want to see your creative side too! We're inviting you to create original content related to the Halving and its potential impact on the future of Bitcoin & Citrea. To help you create the best content possible, we've got resources and support available in our Discord. For the submission details and prizes, see our Halving Campaign blog

We can't wait to see what our amazing community comes up with! The Halving is a time to celebrate the future of Bitcoin, and Citrea is here to help lead the way!

The main squeeze: Citrea launches the Halving Campaign, inviting the community to showcase their knowledge and creativity for a chance to win exclusive prizes and shine amongst the Citrea community. 

Alpha for Next Month

March has been an incredible month of unveiling for us and we are extremely excited for April.

Here is a sneak peek at what to expect in April:

  • Bitcoin Halving and Halving Campaign recipients to be announced
  • Modular Meetup in Dubai with Celestia, Hyperlane, Cartesi and Citrea 
  • Testnet preparations and unveiling milestones as we are nearing the testnet phase

Follow us on twitter to stay updated. Join our discord for more alpha and community support.