:py:mod:`ggmpc.eddsa`
=====================

.. py:module:: ggmpc.eddsa

.. autoapi-nested-parse::

   EdDSA threshold signing library. 



Module Contents
---------------

Classes
~~~~~~~

.. autoapisummary::

   ggmpc.eddsa.Eddsa




.. py:class:: Eddsa(curve)

   Threshold signing over the EdDSA cryptosystem.

   :param curve: The EdDSA curve to use.

   :type curve: ggmpc.Curve

   .. py:method:: secret_generate()

      Generate a secret that can be used as a contribution in DKG.

      :return: A secret.

      :rtype: dict


   .. py:method:: key_share(i, t, n, sk=None)

      Generate shares for player at index `i` of key split `(t,n)` ways.

      :param i: Player index.

      :type i: int

      :param t: Signing threshold.

      :Type t: int

      :param n: Number of shares.

      :type n: int

      :return: Dictionary of shares. Share at index `i` is a private u-share.
        Other indices are y-shares to be distributed to players at their
        corresponding index.

      :rtype: dict


   .. py:method:: key_combine(P)

      Combine data shared during the key generation protocol.

      :param P: Tuple of shares for every player. Must include player's private
        p-share and n-shares received from all other players.

      :type P: tuple

      :return: Dictionary of shares. Share at player's index is a private p-share.
        Other indices are j-shares to be used when generating signing shares.

      :rtype: dict


   .. py:method:: sign_share(M, S)

      Create signing shares.

      :param M: Message to sign.

      :type M: bytes

      :param S: Tuple of shares for each signer. Must include player's private
        p-share and j-shares received from all other signers.

      :type S: tuple

      :return: Dictionary of shares. Share at signer's index is a private x-share.
        Other indices are r-shares to be distributed to signers at their
        corresponding index.

      :rtype: dict


   .. py:method:: sign(M, S)

      Sign a message.

      :param M: Message to sign.

      :type M: bytes

      :param S: Tuple of shares for each signer. Must include signer's private
        x-share and r-shares received from other signers.

      :type S: tuple

      :return: Signature share to be combined with all other signers' signature
        shares.

      :rtype: dict


   .. py:method:: sign_combine(S)

      Combine signature shares to produce the final signature.

      :param S: Tuple of gamma-shares for each signer.

      :type S: tuple

      :return: Fully reconstructed signature.

      :rtype: dict


   .. py:method:: verify(M, sig)

      Verify a signature.

      :param M: Signed message.

      :type M: bytes

      :param sig: Signature.

      :type sig: dict

      :return: True if signature is valid; False otherwise.

      :rtype: bool