README
¶
MPC service 
MPCService allows deploying a multi-party computation service. It implements Go based services that can play a role of an MPC node, or a data provider able to participate in an MPC protocol evaluating a function in a privacy-preserving way. Moreover, a manager (meeting point) of the service is implemented, providing a web interface for requesting computations and handling connections between data providers and MPC nodes. The manager serves purely as a connector and an interface, and has no access to the data.
The service needs minimal effort to be deployed (not only locally, but also over WAN), since it is fully dockerized. It uses SCALE-MAMBA as the underlying MPC library.
- Try it out!
- Deploying an MPC service with decentralized MPC nodes, data providers, and a manager with GUI
- Requesting computations and MPC protocol
- About the code
Try it out!
Git clone the repository and navigate yourself in local_test folder. Assuming that
docker and docker-compose are installed, simply run
docker-compose up
After the docker images are built (this may take a while, mostly due to the installation of SCALE-MAMBA and its dependencies) the service will locally deploy 4 MPC nodes, a data provider, and a manager. Use your web browser to navigate yourself to http://localhost:4100.
Use the provided GUI to request a privacy-preserving computation using MPC.
Deploying an MPC service with decentralized MPC nodes, data providers, and a manager with GUI
The software is preferred to be run in docker containers, see the below explanations. Optionally, to run it directly from Go code
check the dockerfiles in folders mpc_node, data_provider, and manager to see how to install
and set up SCALE-MAMBA (and its dependencies) to be compatible with MPCService.
Connectivity requirements
To run an MPC node, a minimal requirement is that the node has an address and an open port, on which the other MPC nodes can reach it and start an MPC protocol.
To run a manager (a meeting point for the MPC nodes) and a GUI for requesting computations, a server with an address and two open ports is needed.
Access and identity management
To manage who can participate in the system, SSL certificates should be created for each participating service. For example, you can use certstrap (or other similar tools). Create a Certificate Authority:
./certstrap init --common-name "RootCA"
Create a private key and a signed certificate of the manager by the following (the domain should be the address where the manager will be reachable):
./certstrap request-cert --common-name manager -domain managers.domain.com
./certstrap sign manager --CA RootCA```
For the participating MPC nodes and data providers create the certificates similarly (common name should be the name of each provider, see the details bellow).
Running a manager
Set up .env
Specify in the .env file in the MPCService repository the two ports on which the manager will be
available. For example
GUI_PORT=4000
MANAGER_PORT=4001
indicates that on port 4009 a GUI in a web browser is available and on port 4001 it expects that MPC nodes and data providers will connect to it.
Certificates
The manager should have a certificate signed by the certificate authority in which the domain
(DNS address) is specified. Name the certificate and the secret key manager.crt and manager.key,
respectively, and place them into folder key_management/keys_certificates. Place also the certificate
of the certificate authority in the same folder named as RootCA.crt.
Deployment
Run
docker-compose up manager
in the main repository. Check the http://localhost:GUI_PORT, where the GUI
should be available.
Running an MPC node
Set up .env
Specify in the .env file in the MPCService repository the following parameters. NODE_NAME is the name
of the MPC node, NODE_ADDRESS is the address on which the node can be reached, NODE_PORT is the
opened port through which it will be communicating with other nodes, and MANAGER_ADDRESS is the
address and port to reach the manager. For example
NODE_NAME=SuperMPCNode
NODE_ADDRESS=kraken.xlab.si
NODE_PORT=4020
MANAGER_ADDRESS=kraken.xlab.si:4001
Certificates
An MPC node should have a certificate signed by the certificate authority in which the common name
is specified and should match NODE_NAME. Name the certificate and the secret key with NODE_NAME, for
example SuperMPCNode.crt and SuperMPCNode.key, respectively, and place them into the folder
key_management/keys_certificates. Place also the certificate
of the certificate authority in the same folder named as RootCA.crt.
Deployment
Run
docker-compose up mpc_node
in the main repository. Check on the manager's GUI if the node is connected to the system.
Providing datasets for the MPC
The system is designed to work with datasets in CSV format. The assumption is that a dataset
is given in a file ending with .csv: in the first row the names of the columns should be given
while all the other fields should be numerical values. See
data_provider/datasets/breast_canser_dataset.csv for an example. The MPC nodes can compute on one
dataset or join multiple ones, without knowing the data in plaintext.
Datasets that MPC nodes can use, can be provided in two ways:
- as a dataset provider: run a dataset providing service that connects to the manager and shares provided datasets (see bellow)
- with a link: use the GUI functionality on the webpage of the manager to split and encrypt the dataset you want to offer to the MPC nodes. Upload it to a preferred storage provider and share it with a link. The link should be downloadable. This process splits the dataset in MPC shares that only selected nodes can access and use it in an MPC protocol.
While the latter process is self-explanatory, we explain in the following how to run a dataset provider service.
Set up .env
Specify in the .env file in the MPCService repository the following two parameters:
DATA_PROVIDER_NAME is the name
of the data provider, MANAGER_ADDRESS is the
address and port to reach the manager, and SHARE_WITH specifies the names of the MPC nodes
with which the dataset provider is willing to share (encrypted parts) of its data
(one can set it to all). For example
DATA_PROVIDER_NAME=SuperDataProvider
MANAGER_ADDRESS=kraken.xlab.si:4001
SHARE_WITH=SuperMPCNode1,SuperMPCNode2,SuperMPCNode3,SuperMPCNode4
Certificates
A data provider should also have a certificate signed by the certificate authority.
Name the certificate and the secret key with DATA_PROVIDER_NAME, for
example SuperDataProvider.crt and SuperDataProvider.key, respectively, and place them into folder
key_management/keys_certificates. Place also the certificate
of the certificate authority in the same folder named as RootCA.crt.
Deployment
Put the datasets you want to offer in the folder data_provider/datasets. As explained before, these
should be CSV files. Then run
docker-compose up data_provider
in the main repository. Check in the browser on the manager's address if the datasets are available.
Requesting computations and the MPC protocol
After all the MPC nodes and data providers have been connected to the manager, one can use its GUI to request MPC computations and receive CSV files with the computation results. The GUI should be available at http://manager_address:GUI_PORT that was specified before.
Functions
We have provided a couple
of simple functions that can be used: average (computing the average of the columns), statistics
(computing basis statistical values of the columns of the selected datasets) and k-means (a basis
unsupervised learning algorithm giving centers of clusters in data).
More functions can be added. In folder computation/scale_files/MPCService/function you can add additional
functions that need to be written in MAMBA language (see SCALE-MAMBA
documentation), see also the provided examples.
MPC protocol
Currently, the system is predefined to use exactly 3 nodes to evaluate an MPC computation using a maliciously secure Shamir secret sharing based MPC protocol, in which the security assumption is that the majority of nodes are not corrupted (at most one can be corrupted to guarantee the privacy of the data). Since SCALE-MAMBA supports also other protocols and more nodes, the software can be modified/upgraded to different protocols with a bit of work.
Upgrading the system for a particular application
Note: What the software does NOT implement is the management of who can request computations. In this version, everyone that can connect to the manager can request any of the offered computations on an arbitrary offered datasets. Implementing this part heavily depends on the application of the MPC service. For example, if MPC service is used in a Data Market, only users that have paid for the computation should be allowed to request it, and this should be checked by all the participating MPC nodes to keep the system decentralized.
About the code
The code was developed for the KRAKEN project where an MPC service was deployed for evaluating privacy preserving computations in a data market. This is a stand-alone version of it, that could be used in other scenarios.
Test and code coverage
The code was developed with CI and unit tests that help improve the quality, see reports of tools on the quality of it.
Contributions
We are more than happy to accept improvements of the code. Please open a Pull Request or an Issue to report a bug.
License
The code is licensed under the MIT license.
Documentation
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There is no documentation for this package.
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