Atlas Transparency Log Service

A cryptographically secure, append-only storage system for manifests with verifiable transparency log capabilities. Originally designed for Content Authenticity Initiative (C2PA) manifests but supports any structured content requiring tamper-evident storage.

⚠️ Disclaimer: This project is currently in active development. The code is not stable and not intended for use in production environments. Interfaces, features, and behaviors are subject to change without notice.

Features

• Verifiable Transparency Log: Merkle tree-based proof system for manifest inclusion
• Cryptographic Security: Ed25519 signatures and SHA384 hashing via atlas-common
• Multiple Content Formats: Support for JSON, CBOR, and binary manifests
• Append-Only Guarantee: Immutable storage with sequence numbers
• Proof Generation: Inclusion and consistency proofs for third-party verification
• RESTful API: Easy integration with existing systems

Documentation

• Architecture Documentation - Detailed system design and implementation details
• API Reference - Complete API endpoint documentation

Quick Start

Prerequisites

• Rust 1.70+
• MongoDB 4.0+
• OpenSSL development libraries
• Docker and Docker Compose (optional)

Installation

Option 1: Local Development

1. Clone the repository:

git clone https://github.com/IntelLabs/atlas-transparency-log.git
cd atlas-transparency-log

2. Build the project:

cargo build --release

3. Set up environment variables:

export MONGODB_URI="mongodb://localhost:27017"
export DB_NAME="atlas_manifests"
export SERVER_HOST="0.0.0.0"
export SERVER_PORT="8080"
export KEY_PATH="transparency_log_key.pem"

4. Run the service:

cargo run --release

Option 2: Docker Deployment

1. Clone the repository:

git clone https://github.com/IntelLabs/atlas-transparency-log.git
cd atlas-transparency-log

2. Build and run with Docker Compose:

docker-compose up -d

3. Check service health:

curl http://localhost:8080/merkle/root

The service will start at http://localhost:8080.

Usage Examples

Store a Manifest

# JSON manifest
curl -X POST http://localhost:8080/manifests/my-manifest-123 \
  -H "Content-Type: application/json" \
  -d '{
    "manifest_type": "image",
    "data": "example content"
  }'

# CBOR manifest
curl -X POST http://localhost:8080/manifests/my-manifest-456 \
  -H "Content-Type: application/cbor" \
  --data-binary @manifest.cbor

# Binary manifest with type parameter
curl -X POST http://localhost:8080/manifests/my-manifest-789?manifest_type=video \
  -H "Content-Type: application/octet-stream" \
  --data-binary @manifest.bin

# C2PA URN format
curl -X POST http://localhost:8080/manifests/urn:c2pa:123e4567-e89b-12d3-a456-426614174000 \
  -H "Content-Type: application/json" \
  -d '{"manifest_type": "model", "data": "ML model manifest"}'

Get Inclusion Proof

curl http://localhost:8080/manifests/my-manifest-123/proof

Response:

{
  "manifest_id": "my-manifest-123",
  "leaf_index": 42,
  "leaf_hash": "base64_hash...",
  "merkle_path": ["hash1", "hash2", "hash3"],
  "root_hash": "base64_root_hash...",
  "tree_size": 100
}

Verify Inclusion Proof

curl -X POST http://localhost:8080/merkle/verify \
  -H "Content-Type: application/json" \
  -d '{
    "manifest_id": "my-manifest-123",
    "leaf_index": 42,
    "leaf_hash": "base64_hash...",
    "merkle_path": ["hash1", "hash2", "hash3"],
    "root_hash": "base64_root_hash...",
    "tree_size": 100
  }'

API Reference

Manifest Operations

Merkle Tree Operations

Query Parameters

List Manifests (GET /manifests)

• limit - Maximum number of results (default: 100)
• skip - Number of results to skip (default: 0)
• manifest_type - Filter by manifest type
• format - Filter by content format (json/cbor/binary)

Consistency Proof (GET /merkle/consistency)

• old_size - Old tree size
• new_size - New tree size

Development

Running Tests

# Run all tests
cargo test

# Run with output
cargo test -- --nocapture

# Run specific test
cargo test test_merkle_tree_multiple_leaves

# Test atlas-common integration
cargo test test_atlas_common_integration

Project Structure

atlas-transparency-log/
├── Cargo.toml               # Dependencies including atlas-common
├── README.md
├── ARCHITECTURE.md
├── Dockerfile               # Docker container configuration
├── compose.yml              # Multi-service deployment
└── src/
    ├── main.rs              # HTTP server and API endpoints
    ├── tests.rs             # Integration tests
    └── merkle_tree/         # Merkle tree implementation
        ├── mod.rs
        ├── hasher.rs        # Wrapper for atlas-common
        ├── proof.rs         # Proof structures and traits
        └── tree.rs          # Core tree implementation

Key Dependencies

• atlas-common: Provides standardized hashing (SHA256/384/512) and validation utilities
• actix-web: Web framework for HTTP API
• mongodb: Database driver
• ring: Cryptographic primitives for Ed25519 signatures
• serde: Serialization/deserialization

Security Considerations

1. Private Key Protection: The Ed25519 private key is stored in a file. Ensure proper file permissions and consider using a HSM in production.

2. Input Validation: Manifest IDs are validated using atlas-common's validation functions:

   • C2PA URN format: urn:c2pa:UUID[:claim_generator[:version_reason]]
   • Plain UUIDs: 123e4567-e89b-12d3-a456-426614174000
   • Alphanumeric strings with hyphens, underscores, and dots (max 256 chars)

3. Cryptographic Security:

   • SHA384 hashing (default) via atlas-common
   • Constant-time hash comparison to prevent timing attacks
   • Ed25519 signatures for content authenticity

4. Size Limits: Maximum manifest size is 10MB to prevent DoS attacks.

5. Append-Only: No deletion or modification operations are supported to maintain log integrity.

Performance

• Proof Generation: O(log n) time complexity
• Storage: Linear growth with number of manifests
• Verification: Constant time for individual proofs
• Tree Reconstruction: O(n) on startup if needed
• Hashing: Optimized SHA384 implementation via atlas-common

Troubleshooting

Docker Issues

# Check container logs
docker-compose logs atlas_service

# Rebuild containers
docker-compose build --no-cache

# Check container health
docker-compose ps

MongoDB Connection Failed

# Check MongoDB is running
docker-compose logs mongodb

# Verify connection string
docker exec -it atlas_mongodb mongosh

Key Generation Failed

# Check write permissions
ls -la transparency_log_key.pem

# Generate key manually
openssl genpkey -algorithm Ed25519 -out transparency_log_key.pem

Hash Validation Errors

# Test hash validation
curl -X POST http://localhost:8080/manifests/test \
  -H "Content-Type: application/json" \
  -d '{"test": "data"}'

# Check logs for validation details
docker-compose logs atlas_service

Large Manifest Rejection

• Default limit is 10MB
• Adjust MAX_MANIFEST_SIZE in main.rs if needed

Environment Variables

Acknowledgments

• C2PA - Content Authenticity Initiative
• RFC 6962 - Certificate Transparency
• MongoDB - Database
• Actix Web - Web framework