tinysig

Pure-Python implementation of a threshold ecdsa signature scheme based on a secure multi-party computation (MPC) protocol for evaluating arithmetic sum-of-products expressions via a non-interactive computation phase.

Installation and Usage

This library is available as a package on PyPI:

python -m pip install tinysig

The library can be imported in the usual way:

import tinysig
from tinysig import *

Basic Example

This implementation includes the emulation of a network comprised of computing nodes and clients. We can either deploy a network for DSA or ECDSA. In this example, we will show the Elliptic Curve version with 3 nodes and 1 client with id set to 1.

>>> N = 3; C = 1; client_id = 1

To kick things off, let's initialize the network using ECDSA with the P-256 curve:

>>> ecdsa_setup = ECDSASetup(curve="P-256")
>>> ecnet = ThresholdSignature(N, C, setup=ecdsa_setup)

The first protocol involves distributing a key triple among the nodes:

>>> ecnet.distributed_key_generation_protocol(client_id)

The signature protocol unfolds in two phases: the preprocessing phase and the signing phase. Let's run the preprocessing phase:

>>> ecnet.ts_prep_protocol(client_id)

After defining a message we can sign it as follows:

>>> message = "Let me tell you a secret about Nillion."
>>> ecnet.ts_online_protocol(message, client_id)

We run the following to print the signature owned by the client (ID=1):

>>> ecnet.print_signature(client_id)

For a deeper dive, please check the demos folder.

Development

All installation and development dependencies are fully specified in pyproject.toml. The project.optional-dependencies object is used to specify optional requirements for various development tasks. This makes it possible to specify additional options (such as docs, lint, and so on) when performing installation using pip:

python -m pip install .[docs,lint]

Documentation

The documentation can be generated automatically from the source files using Sphinx:

python -m pip install .[docs]
cd docs
sphinx-apidoc -f -E --templatedir=_templates -o _source ../src && make html

Testing and Conventions

All unit tests are executed and their coverage is measured when using pytest (see the pyproject.toml file for configuration details):

python -m pip install .[test]
python -m pytest

Style conventions are enforced using Pylint:

python -m pip install .[lint]
python -m pylint src/tinysig

Contributions

In order to contribute to the source code, open an issue or submit a pull request on the GitHub page for this library.

Versioning

The version number format for this library and the changes to the library associated with version number increments conform with Semantic Versioning 2.0.0.

Publishing

This library can be published as a package on PyPI by a package maintainer. First, install the dependencies required for packaging and publishing:

python -m pip install .[publish]

Ensure that the correct version number appears in pyproject.toml, and that any links in this README document to the Read the Docs documentation of this package (or its dependencies) have appropriate version numbers. Also ensure that the Read the Docs project for this library has an automation rule that activates and sets as the default all tagged versions. Create and push a tag for this version (replacing ?.?.? with the version number):

git tag ?.?.?
git push origin ?.?.?

Remove any old build/distribution files. Then, package the source into a distribution archive:

rm -rf build dist src/*.egg-info
python -m build --sdist --wheel .

Finally, upload the package distribution archive to PyPI:

python -m twine upload dist/*

Disclaimer

Please note that tinysig implementation is a prototype implementation of the protocol presented here and is only meant for educational purposes. The library is not audited and should not be used in production environments.

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE