Installation

pip install pypaillier

The distribution is pypaillier; the import name is paillier. PyPI would not take paillier as a project name, and there was no reason to carry that into the API — every example in this documentation says import paillier.

What actually gets installed

A compiled Rust extension. No compiler and no system GMP are required: GMP is built and linked statically into the wheel when the package is built.

Wheels are built separately for each CPython version — 3.10, 3.11, 3.12 and 3.13 — and that is a deliberate refusal of abi3.

Why not abi3

One wheel for every version looks more convenient than four. But a compatibility tag you cannot trust is worse than no tag at all, and the failure mode is real: an extension tagged abi3 while actually using an unstable symbol installs perfectly and then dies on import on the first interpreter that removed the symbol.

A per-version wheel cannot lie about compatibility: either it was built for this interpreter or it does not exist.

The platform tag is manylinux_2_17 (also known as manylinux2014), the glibc floor that installs on essentially any live Linux.

Building from source

You need stable Rust and maturin:

pip install maturin
maturin build --release
pip install target/wheels/paillier-*.whl

Or straight into the current environment, with no intermediate wheel:

maturin develop --release

Do not build without --release

In a debug build, safe-prime generation takes minutes instead of seconds, and the constant-time measurements mean nothing at all.

Verifying

import paillier
paillier.__version__

The version comes from Cargo.toml at build time rather than being typed in a second place: two copies of a number drift apart silently, and a drifted version lies about which code is installed.