zkSync Era: A ZK Rollup For Scaling Ethereum

zkSync Era is a layer 2 rollup that uses zero-knowledge proofs to scale Ethereum without compromising on security or decentralization. Since it's EVM compatible (Solidity/Vyper), 99% of Ethereum projects can redeploy without refactoring or re-auditing a single line of code. zkSync Era also uses an LLVM-based compiler that will eventually let developers write smart contracts in C++, Rust and other popular languages.

How to use

This repo contains a mixture of witness generation harness (that runs block's code and produces circuit-specific witness parts) and basic examples of full block proof workflow execution, that is:

• create a necessary number of circuits of each unique basic type (so called scheduling)
• aggreagte proofs over them
• run the final state "scheduler" circuit that verifies logical validity of scheduling (feeding outputs to inputs) and attest that aggregation is a result of recursive verification of the scheduled sequence

It's easy to run

Get some modern Rust version (at least that supports Rust 2021 and const generics, but usually latest nightly is also a good option) and run

cargo test basic_test  --release -- --nocapture

It may be a little verbose, but it's a full end to end test that:

• sets up basic environment - empty state tree with added "system" level contracts
• creates some dummy information about previous state of the chain (only state root is necessary)
• runs a contract from https://github.com/vladbochok/test-contract as from address 0x8001 that is a contract call without a calldata and particular meaning, but touches the most interesting parts of the system: external calls, reverts, precompiles, storage access, events, L2 to L1 messages
• produces witness
• makes as many circuits as needed given some (arbitrary) set of capacity parameters of the form "principal operations per circuit of type T"
• generated verification keys for both basic circuits, recursive aggregation circuits, and "scheduler"
• makes proofs of every stage - basic circuits -> aggregation (leafs and nodes) -> scheduler
• each proof is verified against the corresponding verification key on creation

One can see a lot of .json files in the setup and test_proofs folders. Those are all the intermediate proofs, and if proof exists then example script will skip it's recomputation (whether it's a proof or verification key). So to run the full workflow one can remove all of those, or some of those.

Running regeneration of setup files

Will regenerate setup parameters (geometry, verification keys, finalization hints and padding proofs)

cargo run --release --bin geometry_config_generator
cargo test --release test_run_create_base_layer_vks_and_proofs
cargo test --release test_run_create_recursion_layer_vks_and_proofs

License

zkSync Era is distributed under the terms of either

• Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Official Links

• Website
• GitHub
• Twitter
• Twitter for Devs
• Discord

Disclaimer

zkSync Era has been through lots of testing and audits. Although it is live, it is still in alpha state and will go through more audits and bug bounties programs. We would love to hear our community's thoughts and suggestions about it! It is important to state that forking it now can potentially lead to missing important security updates, critical features, and performance improvements.