# nfc-tools/mfoc

Mifare Classic Offline Cracker

Repository: https://github.com/nfc-tools/mfoc
Canonical: https://ross.abutalabs.com/products/mfoc
Language: C
License: GPL-2.0
License Family: copyleft
Last push: 2024-07-17T18:25:08+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 4190, "days_push": 777, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1423, forks 283 (observed 2026-08-28T04:04:41.162444+00:00)

## What it is
MFOC is an open-source C implementation of the offline nested attack for recovering authentication keys from MIFARE Classic NFC cards. It requires at least one known key (default or user-provided) to recover keys from a target card.

## Use cases
- recover keys from a MIFARE Classic card
- audit NFC card security with a nested attack
- find default or unknown keys on MIFARE tags
- test MIFARE Classic authentication offline
- penetration test RFID access cards

## When to choose
- you need to recover MIFARE Classic keys offline using a known key
- you work with libnfc-compatible NFC readers on Linux/macOS
- you are doing security research or penetration testing of RFID systems

## When to avoid
- you target MIFARE DESFire, Ultralight, or other non-Classic card types
- you need a GUI or automated scanning workflow
- you have no known key for the target card

## Facets
- artifact type: cli-tool
- maturity: maintenance
- function: security, cryptography, cli
- domain: security, hardware, developer-tools
- platform: windows, cli
- tags: mifare-classic, nfc, key-recovery, nested-attack, rfid, linux, macos

## Member repositories
- nfc-tools/mfoc (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:41.162444+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 2026-08-30T04:37:39.468608+00:00, confidence not recorded.
  - readme: https://github.com/nfc-tools/mfoc (fetched 2026-08-28T04:04:41.162444+00:00, sha 8e19eb84d33b)
- Data as of 2026-08-30T08:39:29.467469+00:00.