Today, Citrea Team unveils Citrea, the inaugural ZK Rollup designed to elevate Bitcoin’s blockspace capabilities through zero-knowledge technology. Departing from traditional scalability solutions that move security and demand off-chain, Citrea introduces an approach to scale Bitcoin comprehensively 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 altering its consensus rules.
The prevalent issue with creating new blockspace solutions lies in their inability to inherit Bitcoin’s fundamental properties of security, decentralization, and censorship resistance. Citrea addresses this challenge by scaling the entirety of Bitcoin’s blockspace using zero-knowledge proofs, offering a secure and decentralized alternative. It does so using BitVM as the bridging mechanism between the rollup and the Bitcoin blockchain.
BitVM allows the bridge to be set up between the rollup operator (the prover in the BitVM), and some set of monitors (the verifiers in the BitVM). This allows the operator to be penalized and have bonded funds confiscated by any of the verifiers if they attempt to process an inaccurate withdrawal. The BitVM instance, if challenged by a verifier during withdrawal, would actually verify the full Zero Knowledge Proof in the BitVM challenge-response process.
As the demand for Bitcoin blockspace continues to soar, demonstrated by increasing fee rates and heightened interest, existing scalability proposals fall short in addressing the growing need for inclusion in the blockspace, the announcement said. While some solutions redirect demand to separate consensus protocols or sidechains, Citrea aims to stand out by actively and efficiently utilizing Bitcoin blockspace verifiably without compromising its core principles.
Citrea’s zero-knowledge rollup creates an execution shard, batching multiple transactions with minimal data essential for on-chain verification. This method allows Citrea to maximize the efficient utilization of underlying blockspace while maintaining the full security of Bitcoin’s Layer 1.
The platform’s mission is to advance Bitcoin into the “next phase”, per the announcement, positioning it as the foundation for the world’s financial infrastructure. Citrea’s architecture goal is to provide a modular world for Bitcoin, creating consistent fee revenue for miners, trustlessly scaling BTC, and offering developers a versatile environment for building applications on Bitcoin.
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