Privacy
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Updated 11/26/2025
What is
Sigma Protocols?
Zero-knowledge proof protocols native to Ergo that enable privacy features and complex cryptographic conditions without trusted setup.
Sigma Protocols (Σ-protocols) are a class of zero-knowledge proofs built into Ergo's core. They allow proving knowledge of secrets (like private keys) without revealing them, enabling privacy features, multi-signature schemes, and complex access control. Unlike zk-SNARKs, Sigma Protocols require no trusted setup ceremony.
Key Points
- Prove knowledge without revealing the secret
- No trusted setup required (unlike zk-SNARKs)
- Native to ErgoScript - use in any smart contract
- Composable: AND, OR, THRESHOLD combinations
- Enable selective disclosure (prove age without revealing birthdate)
- Power ErgoMixer and privacy applications
Use Cases
1
Private transactions via ErgoMixer
2
Multi-signature with hidden signers (ring signatures)
3
Age/credential verification without revealing data
4
Atomic swaps with privacy guarantees
5
Voting systems with verifiable anonymity
Technical Details
Sigma Protocols in Ergo support Schnorr signatures, Diffie-Hellman tuples, and their compositions. ErgoScript's `proveDlog(x)` proves knowledge of discrete log, `proveDHTuple(g,h,u,v)` proves DDH relations. These can be combined with AND (&&), OR (||), and THRESHOLD (atLeast) operations to create complex spending conditions.
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Frequently Asked Questions
Questions about Sigma Protocols
Common questions about this topic
What is ErgoMixer and how does it work?
ErgoMixer is a non-custodial, trustless mixing service that breaks the link between your input and output addresses. It uses Sigma Protocols to prove you're entitled to withdraw without revealing which deposit was yours. Unlike centralized mixers, there's no trusted party who could steal funds or keep logs.
Explainer
Privacy
Is Ergo a good investment?
This is not financial advice. Ergo has strong fundamentals: fair launch (no VC dump risk), innovative technology (eUTXO, Sigma Protocols, NiPoPoWs), active development, and a cypherpunk ethos. It's a smaller market cap project with higher risk/reward than established chains. Research thoroughly, understand the technology, and never invest more than you can afford to lose.
Comparison
Getting Started
How to escape financial repression with Ergo?
Ergo provides tools for financial sovereignty: self-custody with no third parties, censorship-resistant transactions via PoW, optional privacy with Sigma Protocols, and programmable money without permission. Unlike VC-backed chains, Ergo has no central authority that can freeze funds or comply with sanctions. Your keys, your coins, your freedom.
Solution
Philosophy
What is MEV resistance and why does Ergo have it?
MEV (Maximal Extractable Value) is profit extracted by reordering, inserting, or censoring transactions - think front-running and sandwich attacks. Ergo's eUTXO model provides structural MEV resistance: transactions reference specific boxes (UTXOs), making reordering attacks much harder. There's no shared global state to exploit like in account-based chains.
Explainer
Technology