A quick overview of Kakarot, a zkEVM project invested by Vitalik

Original source: Kakarot

Original compilation: Karen, Foresight News

Kakarot zkEVM is an implementation of the Ethereum Virtual Machine (EVM) written in Cairo. Cairo is a Turing-complete language associated with CairoVM.

CairoVM achieves provable computation by utilizing polynomials and the ZK-STARK proof system. The zkEVM is characterized by its ability to generate provable transactions, which lead to provable blocks. Kakarot is built on top of CairoVM, and every transaction executed on Kakarot is provable.

Kakarot zkEVM enables teams to build and deploy EVM applications. Developers can deploy any Solidity (or any EVM-compatible language) on Kakarot, just like they can on Ethereum or Polygon. Then, their end users can use their usual toolchain (little fox wallet, wallet connection, etc.) to interact with the DApp.

Ultimately, Kakarot will provide interoperability with the native Starknet protocol and composability between protocols, for example, combining TVL in DeFi and user base in GameFi.

Fractal Scaling

Kakarot zkEVM can exist in different forms, first, it can be deployed as a smart contract on top of Starknet L2, thus appearing as (expose) EVM on Starknet (Ethereum RPC, Ethereum transaction, etc.).

Alternatively, Kakarot can be integrated into the stack to deploy L3 zkEVM. This is where the Madara sequencer comes in.

By combining Madara (Starknet full node) and Kakarot (EVM runtime), a L3 zkEVM can be created. The stack is as follows: a Substrate full node, using CairoVM as its execution engine, and Kakarot as the smart contract runtime.

Transactions on Kakarot can be proven and verified on the settlement layer, enabling EVM-compatible fractal scaling.

route map

Phase 1: Kakarot zkEVM on Starknet - Bringing the EVM to Starknet

Kakarot will first exist in Starknet L2 as an onboarded EVM, which will allow developers to deploy their Solidity (or any EVM-compatible language) intelligence directly on Starknet using their familiar toolkits (Foundry, Hardhat, Wagmi, etc.) contract.

Their end users will then be able to interact with their DApps using their usual toolchain (Metamask, Wallet Connect, etc.).

The developer and user experience on Kakarot will be exactly the same as Polygon, Scroll or Ethereum L1.

Phase 2: Kakarot x Madara - L3 zkEVM

Kakarot and Madara will be merged into a unified stack to support L3 zkEVM, as well as L4, L5, etc. Teams will be able to deploy their zkEVM application chain and utilize proof of validity to settle transactions on Starknet.

Why L3? Why provability?

Provability can realize the following functions: calculation under the chain, or calculation on the Layer, and verification on the chain.

L3s utilizing proof-of-validity (like Kakarot) have an interesting but underrated property: the ability to decouple security and decentralization. Users are able to benefit from the security of Ethereum L1 without the same level of decentralization.

Due to the calculation in another layer, the Gas cost is much lower than that of L2, and the performance (TPS) will be higher. L2 is already much cheaper than L1. Rollup scalability stacks and multiplies.

To further reduce Gas costs, proof verification and data availability (DA) can be separated. Starknet L2 can be used only as a proof verification layer, while new data availability solutions such as Celestia or EigenDA can be used to publish transaction data.

Users can opt in to either option, depending on their security requirements. Publishing proofs and transaction data on Starknet is a more secure option, while using DA solutions to publish transaction data is a more cost-effective option.

Phase 3: Kakarot x Madara - type 1 zkEVM

Kakarot and Madara can also be combined to enable type 1 zkEVM.

• Write the Ethereum consensus rules with Cairo in the Madara x Kakarot full node, so as to be able to prove the L1 consensus.
• Switched from Pedersen Merkle Patricia Trie (MPT) to KeccakMPT.

Kakarot will then become a type 1 zkEVM capable of attesting to L1 blocks. This is a more advanced use case that depends on Ethereum's roadmap (most notably Verge). After Verge, keccak may be replaced by poseidon as the hash function of choice for Ethereum. This will help the zkEVM team to be type 1, since the main compatibility hurdle for zkEVM is storage layout, i.e. implementing Keccak MPT in a provably and reasonably cheap way.

Other Research Topics

• Madara enables the Kakarot chain to utilize the Substrate messaging protocol for cross-rollup communication.
• The modularity of Substrate enables the Kakarot chain to innovate using its consensus protocol.
• Substrate's forkless runtime upgrade enables the Kakarot chain to upgrade its EVM version without a hard fork.