Schnorr Zero-Knowledge DLOG Proof

A Rust implementation of the Non-interactive Schnorr Zero-Knowledge Discrete Logarithm (DLOG) Proof scheme with a Fiat-Shamir transformation.

Version

Current version: 0.2.0

Changelog

v0.2.0

• Added comprehensive test suite
• Implemented logging with env_logger
• Added GitHub Actions CI/CD pipeline
• Added code coverage reporting

v0.1.0

• Initial implementation of Schnorr ZK DLOG Proof
• Basic proof generation and verification
• Fiat-Shamir transformation

Overview

This implementation provides a zero-knowledge proof system that allows a prover to demonstrate knowledge of a discrete logarithm without revealing the actual value. The implementation uses the secp256k1 elliptic curve through the k256 crate.

Features

• Non-interactive Schnorr ZK proof generation and verification
• Secure random number generation
• Fiat-Shamir transformation for non-interactivity
• Comprehensive test suite
• Logging support

Implementation Details

Core Components

1. DLogProof struct:

   • t: Commitment value (ProjectivePoint)
   • s: Response value (Scalar)

2. Main Functions:

   • hash_points: Implements the Fiat-Shamir transformation
   • prove: Generates a zero-knowledge proof
   • verify: Verifies a zero-knowledge proof
   • generate_random_scalar: Generates cryptographically secure random values

Security Properties

The implementation ensures:

• Zero-knowledge: The proof reveals nothing about the secret value
• Soundness: Invalid proofs are rejected
• Completeness: Valid proofs are accepted

Dependencies

k256 = { version = "0.13.1", features = ["arithmetic"] }
rand_core = "0.6.4"
sha2 = "0.10.7"
env_logger = "0.11.5"
log = "0.4.22"
tracing = { version = "0.1.40", features = ["log"] }

Usage

Building the Project

cargo build

Running the Example

# Run with default info logging
cargo run

# Run with debug logging
RUST_LOG=debug cargo run

Running Tests

cargo test

Test Coverage

The implementation includes extensive tests covering:

1. Hash Point Generation:

   • Basic functionality
   • Different session IDs
   • Different participant IDs
   • Empty point lists

2. Proof Generation and Verification:

   • Basic prove/verify cycle
   • Wrong session ID handling
   • Wrong participant ID handling
   • Wrong public key handling
   • Multiple proofs for same secret

3. Random Scalar Generation:

   • Uniqueness
   • Range verification

4. Tamper Resistance:

   • Modified response value
   • Modified commitment value
   • Different tampering scenarios

Logging

The implementation uses the log crate with env_logger for configurable logging levels:

• INFO: General execution information
• DEBUG: Detailed values and timing information

Security Considerations

This implementation is for educational purposes. While it implements the core cryptographic operations correctly, it has not been audited for production use.

Documentation

Generating Documentation

To generate the documentation locally, run:

# Make the script executable
chmod +x scripts/generate_docs.sh

# Generate documentation
./scripts/generate_docs.sh

The documentation will be generated in the docs directory. You can view it by opening docs/index.html in your browser.