---
id: rfc3161ng
version: "2.1.3"
license: MIT
license_treatment: permissive
maintenance: abandoned
---

# rfc3161ng — Python implementation of the RFC3161 specification, using pyasn1

License: permissive · Maintenance: abandoned · Downloads: 99.8K/mo

## What it is and what it does

rfc3161ng is a Python client library for RFC3161 cryptographic timestamping services. It lets you request timestamps from remote timestamping authorities to cryptographically prove that data existed at a specific moment in time, and verify those timestamps later. The library handles the protocol details of communicating with timestamping services and parsing the responses.

The package depends on pyasn1, cryptography, requests, python-dateutil, and pyasn1-modules to handle ASN.1 encoding, cryptographic operations, HTTP communication, and date handling. It supports both Python 2.7 and Python 3.6, though the project is no longer maintained. You provide a certificate from your chosen timestamping provider and point the client at their service endpoint.

Use it for:

- Prove the existence and integrity of a document at a specific time for legal or compliance purposes.
- Add cryptographic timestamps to digital signatures to establish when they were created.
- Verify that archived data has not been altered since it was timestamped by a trusted authority.
- Implement audit trails that rely on third-party time attestation for non-repudiation.

## Worth the install?

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

Implements RFC3161 cryptographic timestamping, allowing you to request and verify timestamps from remote timestamping services to prove when data existed.

No. The package is abandoned (last release 2020-10-30) with no active maintenance or security updates. While it has low install friction and a permissive license, using an unmaintained cryptographic library is a security risk. If you need RFC3161 timestamping, seek an actively maintained alternative or evaluate whether the risk of using an outdated library is acceptable for your use case.

## Install

pip install rfc3161ng
uv add rfc3161ng
poetry add rfc3161ng

## Installing rfc3161ng

Before you install: Low install friction with a pure-Python wheel distribution. However, the package is abandoned—last release was 2020-10-30, over 2114 days ago. No active maintenance or security updates should be expected.

License in practice: MIT license (permissive) allows commercial and private use with minimal restrictions, requiring only attribution.

Quickstart:

import rfc3161ng
certificate = open('path/to/cert.crt', 'rb').read()
timestamper = rfc3161ng.RemoteTimestamper('http://freetsa.org/tsr', certificate=certificate)
tst = timestamper.timestamp(data=b'your data')
result = timestamper.check(tst, data=b'your data')

Requires a valid certificate file from the timestamping service provider and network access to the remote timestamping authority.

Verify before relying:

- Whether the package's dependencies (pyasn1, cryptography, requests, python-dateutil, pyasn1-modules) receive active security updates.
- Compatibility with current versions of cryptography and pyasn1 libraries.
- Whether public timestamping providers listed in the documentation remain operational.

## Package facts

- License: MIT (permissive)
- Python support: unspecified
- Install friction: low
- Maintenance: abandoned
- Downloads: 99.8K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

RFC3161 timestamping client, cryptographic timestamp verification, remote timestamping service, timestamp authority protocol, data timestamp proof, RFC3161 implementation, cryptography, timestamp-authority, abandoned

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