Optimism PBC Blog
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Optimism PBC Blog

CANNON CANNON CANNON: Introducing Cannon

Or: Win $50k by Helping Us Hack geohot

Cannon …

… is EVM equivalent

Cannon (github) is the world’s first EVM-equivalent fault proof implementation. Cannon allows us to run the unaltered EVM on L2 with no sacrifices.

… reuses the geth EVM

Cannon takes a fresh approach to fault proofs compared to existing rollups, achieving true EVM equivalence: instead of re-implementing the EVM, it leverages an existing EVM implementation (geth!).

… uses stateless magic

Unlike our previous fault proof design, which re-ran the EVM over a whole transaction on L1, Cannon only needs to execute a single minigeth MIPS instruction on chain. This is a similar approach to existing projects like Truebit, Arbitrum, and Cartesi, but it introduces a key new feature.

… minimizes transaction costs

All existing rollups today submit transaction data to a smart contract, and a hash of the calldata is stored in the state. That overhead imposes costs which must then be passed on to users.

… is coming to prod

(once you all break it!)

Come Break the Cannon!

We now have a bug bounty open on ImmuneFi. The terms are simple: if you’re able to break Cannon, you’ll get $50k. Not to mention the clout you’ll get for hacking a famous hacker!


We would like to give a huge shoutout to geohot for pioneering cannon’s initial implementation and for so many conversations along the way. We’d also like to thank Immunefi for hosting the bug bounty for us!



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