Today, the Citrea team unveils Citrea, the inaugural ZK Rollup designed to leverage Bitcoin's block space capabilities through zero-knowledge technology. Breaking away from traditional scalability solutions that move security and demand off-chain, Citrea offers an approach to end-to-end scaling of Bitcoin with zero-knowledge proofs, ensuring on-chain verifiability and data availability within the Bitcoin network. This positions Citrea as one of the first scaling solutions to enable more complex applications without compromising Bitcoin's security or changing its consensus rules.
The prevailing problem with creating new block space solutions is their inability to inherit Bitcoin's core properties of security, decentralization, and censorship resistance. Citrea addresses this challenge by scaling Bitcoin's entire block space using zero-knowledge proofs, providing a secure and decentralized alternative. This is done using BitVM as a linking mechanism between the collected data set and the Bitcoin blockchain.
BitVM allows setting up a bridge between a rollup operator (the same as in BitVM), and some monitor sets (verifiers in BitVM). This allows the operator to be penalized and have their funds confiscated by any of the investigators if they attempt to process an inaccurate withdrawal. If a BitVM instance is challenged by a validator during a checkout, it will actually check the full zero-knowledge proof in the BitVM challenge response process.
As demand for Bitcoin's block space continues to rise, evidenced by increasing fee rates and rising interest rates, current scalability proposals do not meet the growing need for inclusion in block space, the announcement said. While some solutions redirect the request to separate consensus protocols or sidechains, Citrea aims to stand out by making effective and efficient use of Bitcoin's block space without compromising its core principles.
Citrea's zero-knowledge backlog creates a portion of the implementation, collecting multiple transactions with minimal underlying data for on-chain verification. This method allows Citrea to maximize the efficient use of the underlying block space while maintaining the full security of the first layer of Bitcoin.
The platform's mission is to push Bitcoin to the “next stage,” according to the announcement, and position it as the foundation of the world's financial infrastructure. Citrea's architectural goal is to provide a standardized world for Bitcoin, create stable fee revenue for miners, reliably scale BTC, and provide a versatile environment for developers to build applications on Bitcoin.
