# nccgroup/featherduster

An automated, modular cryptanalysis tool; i.e., a Weapon of Math Destruction

Repository: https://github.com/nccgroup/featherduster
Canonical: https://ross.abutalabs.com/products/featherduster
Language: Python
License: BSD-3-Clause
License Family: permissive
Topics: crypto, cryptography, encryption, security, python, cryptanalysis, exploitation, exploitation-framework, exploit, exploits
Last push: 2021-12-02T16:59:31+00:00

## Health v2 (maintenance only)
Score: 23/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 8, longevity 100
- inputs: {"age_days": 3774, "days_push": 1735, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1137, forks 130 (observed 2026-08-28T04:03:43.845724+00:00)

## What it is
FeatherDuster is an automated, modular cryptanalysis tool from NCC Group that identifies and exploits weak cryptosystems from supplied ciphertext samples. It ships with Cryptanalib, a Python library of crypto attack primitives usable independently.

## Use cases
- break weak encryption from ciphertext samples
- identify the encoding and cipher of unknown ciphertexts
- automate CTF crypto challenge solving
- build custom crypto attack tools in Python
- exploit RSA padding oracle vulnerabilities
- break repeated-key XOR and many-time pad

## When to choose
- you have ciphertext samples and want automated identification and attack of weak crypto
- you're solving CTF crypto challenges
- you want a Python library of classic cryptanalysis primitives

## When to avoid
- you need actively maintained tooling with modern Python support
- you need analysis of modern, correctly-implemented cryptography
- you need a GUI or Windows-native tool

## Facets
- artifact type: cli-tool
- maturity: maintenance
- function: security, cryptography, penetration-testing
- domain: security, penetration-testing
- platform: python, cli
- tags: cryptanalysis, crypto-attacks, ctf, security-tooling, cryptography, linux, macos

## Member repositories
- nccgroup/featherduster (main) score 23

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:03:43.845724+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T06:36:20.500853+00:00, confidence not recorded.
  - readme: https://github.com/nccgroup/featherduster (fetched 2026-08-28T04:03:43.845724+00:00, sha 1f2d3027e739)
- Data as of 2026-08-30T08:39:29.467469+00:00.