# Railgun

> Railgun: Private DeFi protocol. Technology: zero-knowledge proofs.

Part of the Soda Labs Privacy Hub, a neutral directory of the on-chain privacy
landscape: https://www.sodalabs.xyz/privacy-hub

## Key facts

- Entry type: Privacy project
- Category: Private DeFi protocol
- Technology: Zero-knowledge proofs (ZK)
- Website: https://www.railgun.org
- Tags: ZK, shielded pool, DeFi
- Canonical page: https://www.sodalabs.xyz/privacy-hub/railgun

## Overview

Railgun is the most used private DeFi protocol on Ethereum, with 4.5 billion dollars moved cumulatively by early 2026. Its design is notable for keeping the privacy on chain: balances are shielded inside a smart contract and can be spent straight into public DeFi protocols, so users never have to leave the pool to do anything useful. It also ships Private Proofs of Innocence, an on-chain system that lets a user prove their funds are not traceable to a known illicit source without revealing anything else, which is one of the earliest serious attempts at self-service compliance in a shielded pool. Scale of that kind attracts everything: the FBI confirmed that North Korea's Lazarus Group moved over 60 million dollars through it, and compliance vendors now advise treating Railgun-linked flows as elevated risk. As with any shielded pool, privacy strength rises and falls with pool size and user behavior.

## About Zero-knowledge proofs

One party proves a statement about hidden data is true without revealing the data the statement is about. Compared side by side with the other approaches at https://www.sodalabs.xyz/taxonomy.

## Sources

- [Privacy system docs](https://docs.railgun.org/wiki/learn/privacy-system)
- [Private Proofs of Innocence](https://docs.railgun.org/wiki/assurance/private-proofs-of-innocence)
- [Protocol source](https://github.com/Railgun-Privacy)
- [FBI statement, 2022](https://www.fbi.gov/news/press-releases/fbi-confirms-lazarus-group-cyber-actors-responsible-for-harmonys-horizon-bridge-currency-theft)
- [Elliptic guidance](https://www.elliptic.co/blog/analysis/crypto-mixers-and-privacy-protocols-the-sanctions-compliance-implications)

## Related entries

- [Hinkal](https://www.sodalabs.xyz/privacy-hub/hinkal): Private DeFi layer
- [Namada](https://www.sodalabs.xyz/privacy-hub/namada): Multi-asset shielded L1
- [Panther Protocol](https://www.sodalabs.xyz/privacy-hub/panther): Compliant private DeFi
- [Privacy Pools](https://www.sodalabs.xyz/privacy-hub/privacy-pools): Compliant privacy pool
- [Aleo](https://www.sodalabs.xyz/privacy-hub/aleo): Privacy L1
- [Aztec](https://www.sodalabs.xyz/privacy-hub/aztec): Privacy L2