fastecdsa

library3.0.1pypypi✓ verified 89d ago

fastecdsa is a Python library designed for fast elliptic curve digital signatures. It provides an efficient implementation of ECDSA for various standard curves and hash functions, outperforming some other pure Python alternatives. The library is currently at version 3.0.1, with its latest major release in January 2025, and continues to be actively maintained.

auth-security

pip install fastecdsa

github ↗package ↗docs ↗

INSTALL

IMPORT

SIG · FASTECDSA

fastecdsa

auth-securitypythonv3.0.1

Install

1.6s avg

Import

16ms

Disk

17MB

Pass rate

5/ 10

Env Coverage5 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v3.0.1 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

py 3.10–3.920 runs

build_error

glibc

py 3.10–3.920 runs

installs and imports cleanly · install 1.6s · import 0.016s · 19MB

17MB installed

● package 17MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

keys

✓ from fastecdsa import keys

curve

✓ from fastecdsa import curve

ecdsa

✓ from fastecdsa import ecdsa

P256

✓ from fastecdsa.curve import P256

Point

✓ from fastecdsa.point import Point

Generates an ECDSA keypair using the P256 curve, signs a sample message with the private key, and then verifies the signature using the public key and the same curve and hash function.

from fastecdsa import keys, curve, ecdsa from hashlib import sha256 # 1. Generate a keypair private_key, public_key = keys.gen_keypair(curve.P256) # 2. Message to sign (can be string, bytes, or bytearray) message = "This is a test message to be signed." # 3. Sign the message r, s = ecdsa.sign(message, private_key, curve.P256, hashfunc=sha256) # 4. Verify the signature valid = ecdsa.verify((r, s), message, public_key, curve.P256, hashfunc=sha256) print(f"Private Key: {hex(private_key)}") print(f"Public Key (x, y): ({hex(public_key.x)}, {hex(public_key.y)})") print(f"Signature (r, s): ({hex(r)}, {hex(s)})") print(f"Signature Valid: {valid}")

Debug

Known issues

breakingfastecdsa versions 2.x and above exclusively support Python 3.5+. Earlier versions (pre-1.2.1) were compatible with Python 2.7, requiring a Python version upgrade for users migrating from older codebases.

fix

Upgrade your Python environment to 3.9+ and install the latest fastecdsa version.

affects: <2.0.0

gotchaThe library author recommends using more established and thoroughly reviewed cryptographic libraries for security-critical applications, despite fastecdsa's internal security considerations.

fix

Assess the security requirements of your application carefully. For high-stakes security, consider alternatives like `cryptography`.

affects: All versions

gotchaInstallation on Windows and macOS (especially M1/Apple Silicon) can be complex due to the requirement for a C compiler and the `gmp` library. Users often encounter build errors if these dependencies are not correctly set up and discoverable by the Python build process.

fix

Ensure you have a C compiler (e.g., Visual Studio Build Tools on Windows, Xcode Command Line Tools on macOS) and the `gmp` library installed on your system, with their headers and libraries accessible via system paths or environment variables (CFLAGS, LDFLAGS).

affects: All versions

breakingOlder versions of fastecdsa (prior to 2.3.2) contained several security vulnerabilities, including timing attacks and use of uninitialized variables, which could lead to information leakage or denial of service.

fix

Upgrade to fastecdsa version 3.0.1 or at least 2.3.2 to mitigate known vulnerabilities.

affects: <2.3.2

Errors

Common errors & fixes

error: Microsoft Visual C++ 14.0 or greater is required.

During installation on Windows, the C extensions fail to compile because the necessary Microsoft Visual C++ Build Tools are not found.

fix

Install 'Microsoft C++ Build Tools' for Visual Studio (available as a standalone installer or part of Visual Studio).

fatal error: 'gmp.h' file not found #include "gmp.h" OR ld: library not found for -lgmp

The C compiler cannot find the GMP library headers or the linker cannot find the GMP library itself during compilation of fastecdsa's C extensions.

fix

Install the GMP development packages for your system:
- Debian/Ubuntu: `sudo apt-get install libgmp3-dev`
- RHEL/CentOS: `sudo yum install gmp-devel`
- macOS (Homebrew): `brew install gmp`. If this doesn't resolve it, try installing with `CFLAGS="-I$(brew --prefix gmp)/include" LDFLAGS="-L$(brew --prefix gmp)/lib" pip install fastecdsa`.

TypeError: Cannot convert int to bits OR TypeError: an integer is required (got type bytes)

Incorrect argument order or type for the `ecdsa.sign()` or `ecdsa.verify()` functions. A common mistake is swapping the message and private key arguments.

fix

Ensure the correct signature `ecdsa.sign(message, private_key, curve, hashfunc=...)` is used, where `message` is `str`, `bytes`, or `bytearray`, and `private_key` is an `int`. Similarly for `ecdsa.verify((r, s), message, public_key, curve, hashfunc=...)`.

Install Issues

1 verified issue

fatal error: gmp.h: No such file or directoryWindows · Python 3.10 · 3.11 · 3.12 →

Upgrade

Version history

3.0.1latest on PyPI · released Jan 28, 2025

Audit

Dependencies

pythonrequiredRequires Python 3.9 or newer.

gmp (GNU Multiple Precision Arithmetic Library)requiredRequired C library for underlying arithmetic operations. Must be installed on the system.

C compiler (e.g., gcc, clang, MSVC)requiredRequired to compile the C extensions of the library during installation.

pysha3optionalOptional, if using SHA3 hash functions with Python versions older than 3.6. Modern Python versions (3.6+) include SHA3 in `hashlib`.