Welcome to zkay’s documentation!

Zkay is a programming language which enables automatic compilation of intuitive data privacy specifications to Ethereum smart contracts leveraging (homomorphic) encryption and non-interactive zero-knowledge (NIZK) proofs. The zkay package provides a toolchain for compiling, deploying and using zkay contracts.

The zkay language is closely related to Solidity and allows convenient specification of data ownership, reclassification, and private computations. Given a zkay contract, zkay’s compiler automatically transforms it to a Solidity contract that realizes the privacy specification and can be deployed to an Ethereum blockchain.

The core concepts of zkay are introduced in its original research paper.

Contents:

• Getting Started
  • Prerequisites
  • Installation
  • Usage
• Tutorial
  • Example Contract
  • Compilation
  • Local Transaction Testing
  • Deployment
  • Test Deployed Contract
  • Contract Distribution
  • Programmatic Use
• Language Overview
  • Features specific to zkay
  • General Language Features
• Release Notes
  • v0.3.0 (2022-03-21)
  • v0.2.0 (2020-09-01)
  • v0.1.0 (2019-09-20)
• API Reference
  • zkay

Indices and tables

• Index

• Module Index

• Search Page

Security Disclaimer

Zkay is a research project and its implementation should not be considered secure (e.g., it may contain bugs and has not undergone any security review)! Do not use zkay in a productive system or to process sensitive confidential data.

Note that zkay currently relies on zk-SNARKs to enforce its correctness guarantees. These require a trusted setup phase, which is currently performed during local contract compilation and hence can not be trusted if performed by a different user.