Overview
ZKsync OS and Airbender have been developed in parallel to support modular and scalable architecture for ZK Chains.
- Airbender is a new ZK proof system.
- ZKsync OS is a new “operating system” for ZK Chains, allowing chains to choose any Virtual Machine, such as EVM, EraVM, or WASM.
What is Airbender?
Airbender is ZKsync's next-generation proof system, purpose-built to enable efficient ZK proofs of RISC-V bytecode execution. Built on the foundation of highly optimized STARK/FRI implementations, Airbender is designed to support ZKsync's long-term scaling strategy by being fast, cheap, and flexible to a wide range of use cases (without compromising security).
How It Fits with ZKsync OS
ZKsync OS acts as a modular execution layer, allowing chains to run various virtual machines like EVM, EraVM, or WASM. Airbender serves as the proving system that validates the execution of these VMs, encoded in RISC-V bytecode.
Key Features
- RISC-V 32I+M instruction set
- AIR constraints
- Optimized DEEP STARK/FRI proofs
- Mersenne31 prime field
- Blake2s + Blake3 hash function
The name “Airbender” is a reference to AIR constraints (Arithmetic Intermediate Representation).
Proving Pipeline
The proving process follows a structured six-stage pipeline designed for optimal performance and resource utilization:
- Stage 1 - Witness Generation: Computes Low-Degree Extensions (LDEs) of witness data and generates trace commitments. This stage establishes the foundational data structures for the proof.
- Stage 2 - Lookup and Memory Argument: Configures lookup tables and memory arguments, establishing the infrastructure for efficient verification of memory operations and table lookups.
- Stage 3 - STARK Quotient Polynomial: Computes the primary STARK quotient polynomial, which encodes the constraint satisfaction proof for the main circuit.
- Stage 4 - DEEP Polynomial: Implements FRI batching optimizations to reduce the overall proof size and verification complexity.
- Stage 5 - FRI IOPP Generation: Produces the final Interactive Oracle Proof of Proximity (FRI proof) that enables efficient verification.
- Stage 6 - SNARK Wrapper: Wrap the final FRI proof into a final FFLONK proof which gets posted and verified onchain.
Get Started
- Get started with the RISC-V Prover tutorial: RISC-V Prover tutorial
- Get started with Docker: Docker with anvil-zksync
- Get started with running prover end-to-end: Guide to run prover