---
id: x25519
version: "0.0.2"
license: unclear
license_treatment: permissive
maintenance: abandoned
---

# x25519 — A pure Python implemention of curve25519

License: permissive · Maintenance: abandoned · Downloads: 302.0K/mo

## What it is and what it does

x25519 is a pure Python implementation of the curve25519 elliptic curve cryptography operations, providing scalar multiplication functions for key exchange. It exposes two main operations: scalar_base_mult() to derive a public key from a private key, and scalar_mult() to compute a shared secret from a private key and peer's public key. Both functions work with 32-byte binary inputs and outputs.

The package has no runtime dependencies and installs as a pure Python wheel, making it portable across platforms. However, it is explicitly slower than C-based implementations like pysodium, as noted in its own documentation. The project has been inactive since its single release in October 2021 and is no longer maintained.

Use it for:

- Educational exploration of curve25519 cryptography without compiled dependencies.
- Prototyping key exchange protocols in environments where C libraries cannot be compiled.
- Implementing ECDH in pure-Python environments where pysodium or libsodium are unavailable.
- Testing or auditing curve25519 behavior against reference implementations.

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

Provides pure Python implementations of curve25519 scalar multiplication operations for Elliptic Curve Diffie-Hellman key exchange and shared secret derivation.

No. The package is abandoned (last release 2021-10-24, no maintenance since), and the author explicitly recommends C implementations like pysodium for actual use. Install only if you need pure Python for educational purposes or an environment where compiled dependencies are impossible; otherwise, use a maintained cryptographic library.

## Install

pip install x25519
uv add x25519
poetry add x25519

## Installing x25519

Before you install: Installation is frictionless (pure Python wheel, no dependencies), but the package has been abandoned since its only release on 2021-10-24 with no subsequent maintenance or updates.

License in practice: Public domain dedication means no license restrictions apply; you may use, modify, and distribute freely without attribution or other obligations.

Quickstart:

from binascii import hexlify
import x25519

private_key = b'1' * 32
public_key = x25519.scalar_base_mult(private_key)
print(hexlify(public_key))

Verify before relying:

- Whether the pure Python implementation is cryptographically constant-time and resistant to side-channel attacks.
- Performance characteristics compared to C-based alternatives like pysodium for production use.
- Whether Python 2 support claim remains valid or if Python 3 only is now required.

## Package facts

- License: not declared (permissive)
- Python support: unspecified
- Install friction: low
- Maintenance: abandoned
- Downloads: 302.0K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

curve25519 python implementation, elliptic curve key exchange, x25519 scalar multiplication, ecdh key agreement, cryptographic key derivation, elliptic-curve, key-exchange, abandoned

[View on SkillFed](https://skillfed.io/packages/x25519) · [View on PyPI](https://pypi.org/project/x25519/)