---
id: hsms
version: "0.3.2"
license: Apache License Version 2.0, January 2004 http://www.apache.org/licenses/ TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 1. Definitions. "License" shall mean the terms and conditions for… (full text in the JSON record)
license_treatment: permissive
maintenance: aging
---

# hsms — Hardware security module simulator for chia bls12_381 signatures

License: permissive · Maintenance: aging · Downloads: 108.2K/mo

## What it is and what it does

HSMS is a command-line tool suite that simulates a hardware security module for the Chia blockchain, allowing you to sign transactions offline using BLS12-381 cryptographic keys. It runs on an air-gapped computer and accepts unsigned spend objects, producing full or partial signatures suitable for multisig scenarios. The package includes utilities to generate secret keys, display public keys, merge multisig signatures, and convert between binary and qrint ASCII formats, plus debugging tools to inspect spend bundles and unsigned spends.

The tool is built on top of Chia's core libraries (chia_base and chialisp_puzzles) and the segno QR code library. It is intended for operators who need to keep signing keys isolated from networked systems, a common requirement in cryptocurrency custody workflows. The aging maintenance status suggests it is stable but not actively developed, so it may lag behind new Chia protocol features.

Use it for:

- Generate and manage BLS12-381 key pairs for Chia blockchain signing on an isolated computer.
- Sign Chia spend bundles offline using hsmgen and hsms, then transfer signatures back to a networked node.
- Create and merge multisig Chia transactions by combining partial signatures from multiple HSM instances.
- Debug and inspect Chia spend bundles and unsigned spends using hsm_dump_sb and hsm_dump_us utilities.
- Convert binary spend data to/from QR code ASCII format for air-gapped key and transaction transfer.

## Worth the install?

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

Provides command-line tools to simulate a hardware security module for signing Chia blockchain transactions using BLS12-381 keys on an air-gapped computer.

Yes, if you are building or operating a Chia node that requires offline transaction signing. The low install friction and permissive license make it straightforward to add. However, verify compatibility with your Chia version and Python environment first, and understand that aging maintenance means you may need to maintain or patch it yourself if the Chia protocol evolves significantly.

## Install

pip install hsms
uv add hsms
poetry add hsms

## Installing hsms

Before you install: Low install friction with a pure-Python wheel distribution. Maintenance status is aging—last release was 267 days ago—so expect minimal active development, though no recent breakage is evident.

License in practice: Licensed under Apache 2.0 (permissive), which allows commercial and derivative use with minimal restrictions; you must retain license notices and attribute changes.

Quickstart:

pip install hsms

from hsms import hsms
# Use command-line tools: hsms, hsmgen, hsmpk, hsmmerge, qrint

On Windows, requires pyreadline as an additional dependency. Air-gapped deployment requires manual key transfer and spend bundle handling outside normal network channels.

Verify before relying:

- Whether the package works with current Chia blockchain protocol versions and chia_base/chialisp_puzzles releases.
- Specific Python version requirements (requires_python is unspecified in metadata).
- Security audit status or review of the BLS12-381 signing implementation.
- Whether the simulator accurately models real HSM behavior for production use.

## Package facts

- License: Apache License Version 2.0, January 2004 http://www.apache.org/licenses/ TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 1. Definitions. "License" shall mean the terms and conditions for… (full text in the JSON record) (permissive)
- Python support: unspecified
- Install friction: low
- Maintenance: aging
- Downloads: 108.2K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

chia hsm simulator, bls12-381 signing tool, hardware security module chia, offline chia transaction signing, multisig spend signing, air-gapped key management, chia spend bundle signer, chia-blockchain, offline-signing, key-management

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