MPC on Solid
MPC on Solid (or Solid-like decentralized settings).
This directory contains the server code, i.e. the code for the encryption agent and the computation agent.
Refer to mpc-app for the companion Solid App for the end users (who want to initiate MPC).
You should correctly set up the MP-SPDZ environment beforehand (not documented here, see MP-SPDZ's doc). Then, you should install the relevant dependencies, as stated in this section, before running the agent services.
For both type of agents, you need to install Python dependencies to run the API endpoint (service):
pip install -r requirements.txt
For Encryption Agent, you also need to install nodejs dependencies to use data fetcher:
npm install
Use tmuxp:
tmuxp load tmux_sessions.yaml
This will start two encryption agents (listening on port 8000 and 8001), three computation agents (listening on port 8010, 8011, 8012) and the Solid App on local machine.
Internally, the computation agents will use port base 5000, 5010 and 5020 to run the MPC players.
You need to run encryption agents (encryption_server.py) and computation agents (computation_server) depending on your need. Each machine/server is expected to run only one encryption agent, or one computation agent.
uvicorn encryption_server:app --port 8000 --reload
Run separate servers by changing the port number.
Remember to configure the authentication credentials as stated later.
PORT_BASE=5000 uvicorn computation_server:app --port 8010
Run separate servers by changing the port number.
You will also want to change PORT_BASE if you are testing locally, otherwise there will be port conflicts (of the running MPC circuit) between server instances. The example uses 5000, 5010 and 5020 as the port bases, which allows each agent to run 10 MPC tasks simultaneously.
Both the encryption agent and computation agent needs to have a meaningful configuration file. In particular, the base_dir needs to be the base directory of the local MP-SPDZ installation.
Configuration file locate at config/encryption_agent.json. Open and modify it to match your setup.
The encryption agent will use an authenticated fetch to retrieve data from user pods.
Our implementaion uses solid-node-client to authenticate the agent as a WebID. Therefore, you need to create a WebID for your encryption agent (or multiple of them) by registering a pod for it.
Then, add https://solid-node-client to the list of trusted apps for the agent user.
Finally, change the content of config/encryption_agent.json to match your agent user: IDP (usually the server address where the agent user is registered), username, and password.
You need to manually create the directory: MP-SPDZ/ExternalIO/DownloadData, where the downloaded data are stored.
Configuration file locate at config/computation_agent.json. Open and modify it to match your setup.
The encryption agent(s) will need to fetch data from the data providers, and then securely send shares of the data to the computation agents. Therefore, the user will need to ensure appropriate permission is set to allow the encryption agent to access the data. Refer to the README of mpc-app for details.