rwadurian/backend/mpc-system

MPC System Deployment Guide

Multi-Party Computation (MPC) system for secure threshold signature scheme (TSS) implementation in the RWADurian project.

Table of Contents

• Overview
• Architecture
• Quick Start
• Configuration
• Deployment Commands
• Services
• Security
• Troubleshooting
• Production Deployment

Overview

The MPC system implements a 2-of-3 threshold signature scheme where:

• 3 server parties hold key shares
• At least 2 parties are required to generate signatures
• User shares are generated dynamically and returned to the calling service
• All shares are encrypted using AES-256-GCM

Key Features

• Threshold Cryptography: 2-of-3 TSS for enhanced security
• Distributed Architecture: Services communicate via gRPC and WebSocket
• Secure Storage: AES-256-GCM encryption for all stored shares
• API Authentication: API key and IP-based access control
• Session Management: Coordinated multi-party computation sessions

Architecture

┌────────────────────────────────────────────────────────────────┐
│                         MPC System                              │
│                                                                 │
│  ┌──────────────────┐        ┌──────────────────┐              │
│  │ Account Service  │        │ Server Party API │              │
│  │  (Port 4000)     │        │  (Port 8083)     │              │
│  │ External API     │        │ User Share Gen   │              │
│  └────────┬─────────┘        └────────┬─────────┘              │
│           │                           │                        │
│           ▼                           ▼                        │
│  ┌──────────────────┐        ┌──────────────────┐              │
│  │   Session        │◄──────►│ Message Router   │              │
│  │   Coordinator    │        │  (Port 8082)     │              │
│  │  (Port 8081)     │        │  WebSocket       │              │
│  └────────┬─────────┘        └────────┬─────────┘              │
│           │                           │                        │
│           ▼                           ▼                        │
│  ┌────────────────────────────────────────────┐                │
│  │          Server Parties (3 instances)      │                │
│  │   ┌──────────┐ ┌──────────┐ ┌──────────┐  │                │
│  │   │ Party 1  │ │ Party 2  │ │ Party 3  │  │                │
│  │   │  (TSS)   │ │  (TSS)   │ │  (TSS)   │  │                │
│  │   └──────────┘ └──────────┘ └──────────┘  │                │
│  └────────────────────────────────────────────┘                │
│                                                                 │
│  ┌────────────────────────────────────────────┐                │
│  │         Infrastructure Services            │                │
│  │  PostgreSQL  │  Redis  │  RabbitMQ         │                │
│  └────────────────────────────────────────────┘                │
└────────────────────────────────────────────────────────────────┘
                           │
                           │ Network Access
                           ▼
              ┌──────────────────────────┐
              │   Backend Services       │
              │   mpc-service (caller)   │
              └──────────────────────────┘

Quick Start

Prerequisites

• Docker (version 20.10+)
• Docker Compose (version 2.0+)
• Network Access from backend services
• Ports Available: 4000, 8081, 8082, 8083

1. Initial Setup

cd backend/mpc-system

# Create environment configuration
cp .env.example .env

# Edit configuration for your environment
nano .env

2. Configure Environment

Edit .env and update the following REQUIRED values:

# Database password (REQUIRED)
POSTGRES_PASSWORD=your_secure_postgres_password

# RabbitMQ password (REQUIRED)
RABBITMQ_PASSWORD=your_secure_rabbitmq_password

# JWT secret key (REQUIRED, min 32 chars)
JWT_SECRET_KEY=your_jwt_secret_key_at_least_32_characters

# Master encryption key (REQUIRED, exactly 64 hex chars)
# WARNING: If you lose this, encrypted shares cannot be recovered!
CRYPTO_MASTER_KEY=$(openssl rand -hex 32)

# API key for server-to-server auth (REQUIRED)
# Must match the MPC_API_KEY in your backend mpc-service config
MPC_API_KEY=your_api_key_matching_mpc_service

# Allowed IPs (REQUIRED - update to actual backend server IP!)
ALLOWED_IPS=192.168.1.111

3. Deploy Services

# Start all services
./deploy.sh up

# Check status
./deploy.sh status

# View logs
./deploy.sh logs

4. Verify Deployment

# Health check
./deploy.sh health

# Test API
./deploy.sh test-api

Configuration

All configuration is managed through .env file. See .env.example for complete documentation.

Critical Environment Variables

Variable	Description	Required	Example
POSTGRES_PASSWORD	Database password	Yes	openssl rand -base64 32
RABBITMQ_PASSWORD	Message broker password	Yes	openssl rand -base64 32
JWT_SECRET_KEY	JWT signing key (≥32 chars)	Yes	openssl rand -base64 48
CRYPTO_MASTER_KEY	AES-256 key (64 hex chars)	Yes	openssl rand -hex 32
MPC_API_KEY	API authentication key	Yes	openssl rand -base64 48
ALLOWED_IPS	Comma-separated allowed IPs	Yes	192.168.1.111,192.168.1.112
ENVIRONMENT	Environment name	No	production (default)
REDIS_PASSWORD	Redis password	No	Leave empty for internal network

Generating Secure Keys

# PostgreSQL & RabbitMQ passwords
openssl rand -base64 32

# JWT Secret Key
openssl rand -base64 48

# Master Encryption Key (MUST be exactly 64 hex characters)
openssl rand -hex 32

# API Key
openssl rand -base64 48

Configuration Checklist

Before deploying to production:

• Change all default passwords
• Generate secure CRYPTO_MASTER_KEY and back it up securely
• Set MPC_API_KEY to match backend mpc-service configuration
• Update ALLOWED_IPS to actual backend server IP(s)
• Backup .env file to secure location (NOT in git!)

Deployment Commands

Basic Operations

./deploy.sh up          # Start all services
./deploy.sh down        # Stop all services
./deploy.sh restart     # Restart all services
./deploy.sh logs [svc]  # View logs (all or specific service)
./deploy.sh status      # Show service status
./deploy.sh health      # Health check all services

Build Commands

./deploy.sh build            # Build Docker images
./deploy.sh build-no-cache   # Rebuild without cache

Service Management

# Infrastructure only
./deploy.sh infra up    # Start postgres, redis, rabbitmq
./deploy.sh infra down  # Stop infrastructure

# MPC services only
./deploy.sh mpc up      # Start MPC services
./deploy.sh mpc down    # Stop MPC services
./deploy.sh mpc restart # Restart MPC services

Debugging

./deploy.sh logs-tail [service]  # Last 100 log lines
./deploy.sh shell [service]      # Open shell in container
./deploy.sh test-api             # Test Account Service API

Cleanup

# WARNING: This removes all data!
./deploy.sh clean

Services

External Services (Exposed Ports)

Service	Port	Protocol	Purpose
account-service	4000	HTTP	Main API for backend integration
session-coordinator	8081	HTTP/gRPC	Session coordination
message-router	8082	WebSocket/gRPC	Message routing
server-party-api	8083	HTTP	User share generation

Internal Services

Service	Purpose
server-party-1	TSS party 1 (stores server shares)
server-party-2	TSS party 2 (stores server shares)
server-party-3	TSS party 3 (stores server shares)
postgres	Database for session/account data
redis	Cache and temporary data
rabbitmq	Message broker for inter-service communication

Service Dependencies

Infrastructure Services (postgres, redis, rabbitmq)
    ↓
Session Coordinator & Message Router
    ↓
Server Parties (1, 2, 3) & Server Party API
    ↓
Account Service (external API)

Security

Access Control

1. IP Whitelisting: Only IPs in ALLOWED_IPS can access the API
2. API Key Authentication: Requires valid MPC_API_KEY header
3. Network Isolation: Services communicate within Docker network

Data Protection

1. Encryption at Rest: All shares encrypted with AES-256-GCM
2. Master Key: CRYPTO_MASTER_KEY must be securely stored and backed up
3. Secure Transport: Use HTTPS/TLS for external communication

Best Practices

• Never commit .env to version control
• Backup CRYPTO_MASTER_KEY to multiple secure locations
• Rotate API keys regularly
• Use strong passwords (min 32 chars)
• Restrict database ports (don't expose to internet)
• Monitor failed authentication attempts
• Enable audit logging

Key Backup

# Backup master key (CRITICAL!)
echo "CRYPTO_MASTER_KEY=$(grep CRYPTO_MASTER_KEY .env | cut -d= -f2)" > master_key.backup

# Store securely (encrypted USB, password manager, vault)
# NEVER store in plaintext on the server

Troubleshooting

Services won't start

# Check logs
./deploy.sh logs

# Check specific service
./deploy.sh logs postgres

# Common issues:
# 1. Ports already in use
# 2. .env file missing or misconfigured
# 3. Database initialization failed

Database connection errors

# Check postgres health
docker compose ps postgres

# View postgres logs
./deploy.sh logs postgres

# Restart infrastructure
./deploy.sh infra down
./deploy.sh infra up

API returns 403 Forbidden

# Check ALLOWED_IPS configuration
grep ALLOWED_IPS .env

# Verify caller's IP is in the list
# Update .env and restart:
./deploy.sh restart

API returns 401 Unauthorized

# Verify MPC_API_KEY matches between:
# 1. This system's .env
# 2. Backend mpc-service configuration

# Check API key
grep MPC_API_KEY .env

# Restart after updating
./deploy.sh restart

Keygen or signing fails

# Check all server parties are healthy
./deploy.sh health

# View server party logs
./deploy.sh logs server-party-1
./deploy.sh logs server-party-2
./deploy.sh logs server-party-3

# Check message router
./deploy.sh logs message-router

# Restart MPC services
./deploy.sh mpc restart

Lost master encryption key

CRITICAL: If CRYPTO_MASTER_KEY is lost, encrypted shares cannot be recovered!

Prevention:

• Backup key immediately after generation
• Store in multiple secure locations
• Use enterprise key management system in production

Production Deployment

Pre-Deployment Checklist

• Generate all secure keys and passwords
• Backup CRYPTO_MASTER_KEY to secure locations
• Configure ALLOWED_IPS for actual backend server
• Sync MPC_API_KEY with backend mpc-service
• Set up database backups
• Configure log aggregation
• Set up monitoring and alerts
• Document recovery procedures
• Test disaster recovery

Deployment Steps

Step 1: Prepare Environment

# On MPC server
git clone <repo> /opt/rwadurian
cd /opt/rwadurian/backend/mpc-system

# Configure environment
cp .env.example .env
nano .env  # Set all required values

# Generate and backup keys
openssl rand -hex 32 > master_key.txt
# Copy to secure storage, then delete:
# rm master_key.txt

Step 2: Deploy Services

# Build images
./deploy.sh build

# Start services
./deploy.sh up

# Verify all healthy
./deploy.sh health

Step 3: Configure Firewall

# Allow backend server to access MPC ports
sudo ufw allow from <BACKEND_IP> to any port 4000
sudo ufw allow from <BACKEND_IP> to any port 8081
sudo ufw allow from <BACKEND_IP> to any port 8082
sudo ufw allow from <BACKEND_IP> to any port 8083

# Deny all other external access
sudo ufw default deny incoming
sudo ufw enable

Step 4: Test Integration

# From backend server, test API access
curl -H "X-API-Key: YOUR_MPC_API_KEY" \
  http://<MPC_SERVER_IP>:4000/health

Monitoring

Monitor these metrics:

• Service health status
• API request rate and latency
• Failed authentication attempts
• Database connection pool usage
• RabbitMQ queue depths
• Key generation/signing success rates

Backup Strategy

# Database backup (daily)
docker compose exec postgres pg_dump -U mpc_user mpc_system > backup_$(date +%Y%m%d).sql

# Configuration backup
tar -czf config_backup_$(date +%Y%m%d).tar.gz .env kong.yml

# Encryption key backup (secure storage only!)

Disaster Recovery

1. Service Failure: Restart affected service using ./deploy.sh restart
2. Database Corruption: Restore from latest backup
3. Key Loss: If CRYPTO_MASTER_KEY lost, all encrypted shares are unrecoverable
4. Full System Recovery: Redeploy from backups, restore database

Performance Tuning

# docker-compose.yml - adjust resources
services:
  session-coordinator:
    deploy:
      resources:
        limits:
          cpus: '2'
          memory: 2G

API Reference

Account Service API (Port 4000)

# Health check
curl http://localhost:4000/health

# Create account (keygen)
curl -X POST http://localhost:4000/api/v1/accounts \
  -H "X-API-Key: YOUR_MPC_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"user_id": "user123"}'

# Sign transaction
curl -X POST http://localhost:4000/api/v1/accounts/{account_id}/sign \
  -H "X-API-Key: YOUR_MPC_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"message": "tx_hash"}'

Server Party API (Port 8083)

# Generate user share
curl -X POST http://localhost:8083/api/v1/shares/generate \
  -H "X-API-Key: YOUR_MPC_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"session_id": "session123"}'

Getting Help

• Check logs: ./deploy.sh logs
• Health check: ./deploy.sh health
• View commands: ./deploy.sh help
• Review .env.example for configuration options

License

Copyright © 2024 RWADurian. All rights reserved.