Crate sigma_rs

Σ-rs: Sigma Protocols in Rust

Σ-rs is a Rust library for constructing zero-knowledge proofs using Sigma protocols (Σ-protocols). It allows proving knowledge of secret data without revealing the data itself.

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What are Sigma Protocols?

Sigma protocols are interactive cryptographic protocols that allow a prover to convince a verifier they know a secret (like a private key) without revealing the secret itself. They follow a simple three-step pattern: commitment, challenge, response.

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Key Features

• Composable: Combine multiple proofs into compound statements
• Generic: Works with any cryptographic group supporting the required operations
• Flexible Hashing: Multiple hash function backends for different use cases
• Non-Interactive Ready: Support for Fiat–Shamir transformation

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Basic Usage

The library provides building blocks for creating zero-knowledge proofs:

1. Define your mathematical relation using LinearRelation
2. Create a Sigma protocol with schnorr_protocol::SchnorrProof
3. Convert to non-interactive using fiat_shamir::NISigmaProtocol
4. Generate and verify proofs using the protocol interface

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Core Components

• traits::SigmaProtocol: The fundamental three-move protocol interface
• linear_relation::LinearRelation: Express mathematical relations over groups
• fiat_shamir::NISigmaProtocol: Convert interactive proofs to standalone proofs
• composition::Protocol: Combine multiple proofs together
• codec: Hash function backends for proof generation

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Σ-rs is designed to be modular, extensible, and easy to integrate into zero-knowledge applications.

Re-exports

pub use fiat_shamir::NISigmaProtocol;

pub use linear_relation::LinearRelation;

Modules

codec

Encoding and decoding utilities for Fiat-Shamir and group operations.

composition

Protocol Composition with AND/OR Logic

duplex_sponge

Duplex Sponge Interface

errors

Error: Error Types for Zero-Knowledge Proofs.

fiat_shamir

Fiat-Shamir transformation for SigmaProtocols.

linear_relation

Linear Maps and Relations Handling.

schnorr_protocol

Implementation of the generic Schnorr Sigma Protocol over a Group.

serialization

Serialization and deserialization utilities for group elements and scalars.

traits

Generic interface for 3-message Sigma protocols.