2CP

This is my dissertation for my MSc in Computing (Artificial Intelligence & Machine Learning) at Imperial College London (2019-20).

Project paper

2CP: Decentralized protocols to transparently evaluate contributivity in Blockchain Federated Learning environments

What's in this repo?

2cp/: This repository contains 2CP, the software framework which implements the Crowdsource Protocol and the Consortium Protocol.

contracts/: The solidity source code for 2CP smart contracts.

experiments/: It also contains the code used to run the experiments described in the project paper, and the corresponding results.

migrations/: Deployment scripts used by Truffle. Not currently needed as 2CP automatically deploys contracts without using Truffle.

scripts/: Miscellaneous scripts to tidy up results files, produce plots, etc.

tests/: Unit tests for 2CP.

Development

Setting up python environment

Recommended:

• Anaconda (install for user)
• Visual Studio Code

It is easiest to create and use a fresh conda environment.

conda create -n proj
activate proj

VSCode should already be set up to use this proj conda environment.

Next, use conda to install pytorch as pip is not supported. We need exactly version 1.4.0 for compatibility with PySyft.

conda install pytorch==1.4.0 torchvision -c pytorch

Use pip to install everything else.

pip install -r requirements.txt

Adding /2cp to PYTHONPATH

Required to run unit tests or experiments. This is really easy with conda. From repo root:

conda develop 2cp

VSCode should already be set up correctly; see .vscode/settings.json and .env. (Followed these instructions)

Setting up IPFS client

Requirements

• IPFS Desktop

Setting up solidity frameworks

Requirements

• Truffle
• Ganache

Setting up simulated blockchain

1. Open the Ganache app.
2. Quick start or set up a new workspace.
3. (Optional, to create a more realistic blockchain) In settings, under Server, turn off automine and set mining block time to 15 seconds (or set to 3 or 4 to make unit tests run more quickly). Need to do this to test behaviour when transactions aren't mined instantaneously.

Alternative: Docker

Best option if not using Windows. Requires only Docker

1. Build the docker image: (in repo root) docker build -t 2cp .
2. Launch the image in interactive mode: docker run -it 2cp
3. Start the ipfs daemon in the background: ipfs daemon &
4. Start the blockchain in the background: ganache-cli --port=7545 &

Running unit tests or experiments

1. Compile the contracts: truffle compile (2CP deploys them automatically when it runs)
2. Spin up a blockchain as above.
3. Start up an IPFS node by opening the IPFS desktop app.
4. Run one of these commands:

• Unit tests: pytest -s (the -s flag displays print statements.)
• MNIST experiments: python experiments/mnist/mnist.py --full (without the --full flag, will just run a quick version for debugging purposes.)
• COVID experiments: python experiments/covid/covid.py --full

Choose which experiments to run by defining changing the experiments dictionary in the mnist.py or covid.py scripts.

Producing plots

python scripts/make_plots.py