pyecsca.ec.params module

Provides functions for obtaining domain parameters from the std-curves repository [STD].

It also provides a domain parameter class and a class for a whole category of domain parameters.

class pyecsca.ec.params.DomainParameters(curve, generator, order, cofactor, name=None, category=None)[source]

Bases: object

Domain parameters which specify a subgroup on an elliptic curve.

curve: EllipticCurve
generator: Point
order: int
cofactor: int
name: Optional[str]
category: Optional[str]
to_coords(coordinate_model)[source]

Convert the domain parameters into a different coordinate model, only possible if they are currently affine.

Parameters:

coordinate_model (CoordinateModel) – The target coordinate model.

Return type:

DomainParameters

Returns:

The transformed domain parameters

to_affine()[source]

Convert the domain parameters into the affine coordinate model, if possible.

Return type:

DomainParameters

Returns:

The transformed domain parameters

class pyecsca.ec.params.DomainParameterCategory(name, description, curves)[source]

Bases: object

A category of domain parameters.

name: str
description: str
curves: List[DomainParameters]
pyecsca.ec.params.load_category(file, coords, infty=True)[source]

Load a category of domain parameters containing several curves from a JSON file.

Parameters:

  • file (Union[str, Path, BinaryIO, IO[bytes]]) – The file to load from.

  • coords (Union[str, Callable[[str], str]]) – The name of the coordinate system to use. Can be a callable that takes as argument the name of the curve and produces the coordinate system to use for that curve.

  • infty (Union[bool, Callable[[str], bool]]) – Whether to use the special InfinityPoint (True) or try to use the point at infinity of the coordinate system. Can be a callable that takes as argument the name of the curve and returns the infinity option to use for that curve.

Return type:

DomainParameterCategory

Returns:

The category.

pyecsca.ec.params.load_params(file, coords, infty=True)[source]

Load a curve from a JSON file.

Parameters:

  • file (Union[str, Path, BinaryIO]) – The file to load from.

  • coords (str) – The name of the coordinate system to use.

  • infty (bool) – Whether to use the special InfinityPoint (True) or try to use the point at infinity of the coordinate system.

Return type:

DomainParameters

Returns:

The curve.

pyecsca.ec.params.load_params_ecgen(file, coords, infty=True)[source]

Load a curve from a file that is output of ecgen.

Parameters:

  • file (Union[str, Path, BinaryIO]) – The file to load from.

  • coords (str) – The name of the coordinate system to use.

  • infty (bool) – Whether to use the special InfinityPoint (True) or try to use the point at infinity of the coordinate system.

Return type:

DomainParameters

Returns:

The curve.

pyecsca.ec.params.load_params_ectester(file, coords, infty=True)[source]

Load a curve from a file that uses the format of ECTester.

Parameters:

  • file (Union[str, Path, BinaryIO]) – The file to load from.

  • coords (str) – The name of the coordinate system to use.

  • infty (bool) – Whether to use the special InfinityPoint (True) or try to use the point at infinity of the coordinate system.

Return type:

DomainParameters

Returns:

The curve.

pyecsca.ec.params.get_category(category, coords, infty=True)[source]

Retrieve a category from the std-curves database at https://github.com/J08nY/std-curves.

Parameters:

  • category (str) – The category to retrieve.

  • coords (Union[str, Callable[[str], str]]) – The name of the coordinate system to use. Can be a callable that takes as argument the name of the curve and produces the coordinate system to use for that curve.

  • infty (Union[bool, Callable[[str], bool]]) – Whether to use the special InfinityPoint (True) or try to use the point at infinity of the coordinate system. Can be a callable that takes as argument the name of the curve and returns the infinity option to use for that curve.

Return type:

DomainParameterCategory

Returns:

The category.

pyecsca.ec.params.get_params(category, name, coords, infty=True)[source]

Retrieve a curve from a set of stored parameters.

Uses the std-curves database at https://github.com/J08nY/std-curves.

Parameters:

  • category (str) – The category of the curve.

  • name (str) – The name of the curve.

  • coords (str) – The name of the coordinate system to use.

  • infty (bool) – Whether to use the special InfinityPoint (True) or try to use the point at infinity of the coordinate system.

Return type:

DomainParameters

Returns:

The curve.