foss_cryptography is a Python free open source library for Elliptic Curves cryptography under the MIT License.
The library provides:
- the basic operations for the generic elliptic curve points: addition, doubling and scalar multiplication
- the ECDSA (Elliptic Curve Digital Signature Algorithm) for non-deterministic and deterministic message signing and signature verification
- a library of parameters of some standard elliptic curves (NIST, etc.)
The main functions of this library are self-contained, and the library doesn't require any external dependencies to perform its core operations.
-
Elliptic Curve Operations: The library includes a module
ellipticCurves.pythat provides essential operations on elliptic curves, such as point doubling, point addition, and scalar multiplication. -
ECDSA Implementation: The
ecdsa.pymodule implements the ECDSA algorithm with non-deterministic and deterministic generation of k (RFC6979), allowing users to sign and verify messages using a provided library of standard elliptic curves.
Install the library
pip install foss-cryptographyClone the library from GitHub
git clone https://github.com/stefanogaspari/foss_cryptography.gitInstall the library dependencies
pip install -r requirements.txtBuild the library
python setup.py bdist_wheelInstall the library
pip install /path/to/wheelfile.whlfrom foss_crypto.ellipticCurves import EllipticCurve
from foss_crypto.secp256k1 import p, a, b
# Initialize an elliptic curve
curve = EllipticCurve(p, a, b)
# Point initialization
P = [x1, y1] # x1 and y1: type int
Q = [x2, y2] # x2 and y2: type int
# Point doubling R = 2 * P
R = curve.double(P)
# Point addition, R = P + Q
R = curve.add(P, Q)
# Scalar multiplication, R = n * P
R = curve.scalar_multiply(n, P)from foss_crypto.ecdsa import ECDSA
from foss_crypto.curves.secp256k1 import p, a, b, origin_G, n
# Define the hash function
hash_function = 'sha256'
# Initialize ECDSA secp256k1 instance
ecdsa = ECDSA(m, a, b, origin_G, n, hash_function)
# Sign a message with a secure random k
# k: int
# message: bytes
# private_key: bytes
# signature: Tuple(bytes, bytes) -> r , s
signature = ecdsa.non_deterministic_sign(k, message, private_key)
# Verify a message
# signature: bytes -> r || s
# message: bytes
# public_key: bytes -> public_key_x || public_key_y
# is_verified: bool
is_verified = ecdsa.verify(signature, message, public_key)from foss_crypto.ecdsa import ECDSA
from foss_crypto.curves.secp256k1 import p, a, b, origin_G, n
# Define the hash function
hash_function = 'sha256'
# Initialize ECDSA secp256k1 instance
ecdsa = ECDSA(m, a, b, origin_G, n)
# Sign a message with a deterministic k (as per RFC6979)
# message: bytes
# private_key: bytes
# signature: Tuple(bytes, bytes) -> r , s
signature = ecdsa.deterministic_sign(message, private_key)
# Verify a message
# signature: bytes -> r || s
# message: bytes
# public_key: bytes -> public_key_x || public_key_y
# is_verified: bool
is_verified = ecdsa.verify(signature, message, public_key)This project is under the MIT License.