Running the System

Prerequisites

• Python 3.12+
• uv (package manager / build tool)
• Docker and Docker Compose (for the containerized demo)

Installation

# Clone the repository
git clone https://github.com/jonco5555/Payment-Scheme.git
cd Payment-Scheme

# Install all dependencies
uv sync

Starting the System

Option A: Local processes

Start all five servers and five clients in the foreground:

bash scripts/run_local.sh

This script:

1. Creates one key share per server and the system public key.
2. Starts servers 0–4 on ports 8000–8004.
3. Waits 3 seconds for servers to bind.
4. Starts clients 0–4 on ports 9000–9004.

Press Ctrl+C to shut everything down.

Option B: Full local demo

Run the demo script that also performs mint and pay operations:

bash scripts/run_demo.sh

This script:

1. Creates one key share per server and the system public key.
2. Runs payment setup to generate fresh keys.
3. Starts all servers and clients.
4. Waits for clients to become ready (health-checks /payment-key).
5. Mints two tokens on client-0.
6. Sends a payment from client-0 to client-1.
7. Prints balances.
8. Simulates omission failures by killing f servers.
9. Performs another payment (client-1 → client-2) under degraded conditions.
10. Prints final balances.

Option C: Docker Compose demo

bash scripts/run_demo_docker.sh

This builds the Docker image, generates keys inside a container, starts all services via docker-compose up -d, and then runs the same demo workflow using curl against the exposed client ports (9000–9004).

Omission failures are simulated by running docker compose stop server-3 and docker compose stop server-4.

Environment Variables

Variable	Used by	Description
CONFIG_PATH	server, client	Path to the YAML config file
SERVER_ID	server	Server identifier (must match servers[i].id in config)
KEY_SHARE_PATH	server	Path to the server's key share .bin file
CLIENT_ID	client	Client identifier
PORT	client	Port for the client's FastAPI server
LOG_LEVEL	all	Logging level (DEBUG, INFO, WARNING, etc.)