Citrea, the first zero-knowledge (ZK) rollup on Bitcoin, came out of stealth yesterday. And Murat Karademir, and Orkun Mahir Kılıç, cofounders of Chainway Labs, discussed everything about it on the latest episode of Unchained Premium.

The Citrea team emphasizes that Bitcoin’s scalability has traditionally been addressed by off-chain solutions, which often compromise on security and decentralization. Citrea proposes a different approach by utilizing zero-knowledge proofs to scale Bitcoin, while ensuring on-chain verifiability and data availability. This method intends to keep Bitcoin’s security and consensus rules intact.

Read more: What Are Zero-Knowledge Proofs?

The need for such an innovation stems from the high demand for Bitcoin’s secure, decentralized, and censorship-resistant blockspace. Current scalability solutions, including sidechains, often create alternative blockspaces that cannot inherit these core properties of Bitcoin. Citrea, in contrast, seeks to scale within the Bitcoin ecosystem itself, using ZK rollups to batch transactions, process them through zkVM, and produce succinct validity proofs. These are then inscribed and verified within the Bitcoin blockchain, a first in Bitcoin’s history.

Karademir and Kılıç’s approach includes the integration of BitVM, which could influence how smart contracts are deployed on Bitcoin. According to them, the rollup’s security model focuses on minimizing trust, and could potentially solve Bitcoin’s security budget issues.