Jan Gorzny

In this talk, we’ll explore the challenges of bringing zero-knowledge proofs as a finality mechanism to the OP Stack. This entirely removes the need for fraud proofs as blocks are equipped with validity proofs. Unfortunately, the OP stack currently changes some EVM semantics and that changes how the circuits for a block prover would need to be constructed. As an example, the deposit transactions introduced by the OP stack don’t have valid signatures -- so the circuits from the PSE for validating blocks that include them don’t work out of the box. These OP stack changes, along with other design decisions of the stack, add challenges to building an EVM equivalent ZK rollup using the stack. We explore these challenges and explain how we overcame them in Zircuit.

In this talk, we’ll describe Zircuit - a zero-knowledge rollup built on the OP stack. We’ll highlight the benefits of building on the OP stack as well as the architecture of Zircuit and its unique features. We’ll highlight the key features that the OP stack provides rollup developers and highlight what needs to be added to make the result use validity proofs instead of fraud proofs. We’ll illustrate how Zircuit built the remaining infrastructure and provide insights into how Zircuit is built differently. Finally, we’ll talk about the security-focused features that makes Zircuit unique.