macOS
Homebrewverified · 100%
brew install bkcracklocal Homebrew formula metadata
brew / rank 4119
Install bkcrack with Homebrew, Nix, zypper
Crack legacy zip encryption with Biham and Kocher's known plaintext attack. Version 1.8.1 via Homebrew; verified from local package data. Also installable with nix: nix profile install nixpkgs#bkcrack.
install
Additional install commands
Linux
Nixverified · 92%
nix profile install nixpkgs#bkcracknixpkgs package indexes · pkgs/by-name/bk/bkcrack/package.nix · source: api.github.com
openSUSE zypperverified · 92%
sudo zypper install bkcrackopenSUSE Tumbleweed package metadata · bkcrack · source: download.opensuse.org
overview
Package summary
Crack legacy zip encryption with Biham and Kocher's known plaintext attack
Project links
Commands and aliases
- bkcrack
history
Project history and usage
bkcrack is a command-line cryptanalysis tool for legacy ZIP encryption, specifically the traditional PKWARE/ZipCrypto scheme. Its package-manager identity is narrow and practical: a small utility installed when a user needs a known-plaintext attack workflow against old encrypted ZIP archives.
Project history
The project was published on GitHub in 2016 and describes itself as an implementation of Eli Biham and Paul C. Kocher's known-plaintext attack on the PKZIP stream cipher. Its documentation explains the ZipCrypto keystream model and frames bkcrack as a way to recover internal keys, remove or change archive passwords, and attempt password recovery.
Adoption history
bkcrack grew from a specialist security tool into a packaged CLI available through Homebrew, Nix, openSUSE/zypper, and upstream GitHub release artifacts for Ubuntu, macOS, and Windows. That distribution pattern reflects a tool useful enough for repeatable incident-response and recovery workflows but still niche compared with general password crackers.
How it is used
Typical use starts with a ciphertext entry and 12 or more bytes of known plaintext, often supplied from another ZIP entry or file. Users run bkcrack to recover the ZipCrypto internal state, then decrypt data, create an unencrypted copy of the archive, change the password, or search for the original password from recovered keys.
Why package nerds care
Package nerds care about bkcrack because it packages a classic academic break of legacy ZIP encryption into a reproducible CLI with cross-platform binaries. It is a reminder that 'ZIP password support' in archive tools historically meant weak ZipCrypto unless AES or another modern scheme was explicitly used.
Timeline
- 1994: Biham and Kocher publish the known-plaintext attack on the PKZIP stream cipher.
- 2016: bkcrack repository is created on GitHub.
- 2020: v1.0.0 appears as the first GitHub release in the current release history.
- 2020s: bkcrack becomes available through Homebrew and other Unix package sets.
Related projects
- Related tools include zip password recovery and auditing utilities, but bkcrack is specifically centered on ZipCrypto known-plaintext recovery rather than generic brute-force cracking.
- The underlying cryptanalytic reference is Biham and Kocher's PKZIP stream-cipher paper, which bkcrack cites directly from its README.
Sources
security posture
Risk level: blue
broad file, network, media, or database tool signal.
Risk classifier
blue risk · medium confidence · tool
Why
- broad file, network, media, or database tool signal
Signals
- text:encrypt
Install behavior
- No Homebrew bottle metadata was recorded.
Recommended review
Before unattended agent use, check whether the tool reads plaintext credentials, writes remote state, publishes artifacts, or shells out to plugins.
executables
Installed executables
| Command | Kind | Exposure | Note |
|---|---|---|---|
bkcrack | executable | indexed executable | Discovered from the local executable index. |
freshness
Version and freshness
These signals separate page generation age, package-manager activity, and upstream release comparison. Version lag is warned only when an evidence URL and comparable versions are present.
page generated2026-08-03
manager version1.8.1
manager updated
local dataunknown
upstreamnot available
latest detectednot detected
- okNo freshness warnings were generated.
install metadata
Package metadata
| Package key | brew:bkcrack |
|---|---|
| Version | 1.8.1 |
| Package manager | Homebrew |
| Homepage | https://github.com/kimci86/bkcrack |
| Repository | https://github.com/kimci86/bkcrack |
| Bottle | not recorded |
| Service | none declared |
source database matches
Other package-manager records
Matches are pulled from external package-manager indexes and kept separate from local Automic Vault package links.
Nix95%
bkcrack
nix profile install nixpkgs#bkcrack- normalized package name match
- Matched by: Bkcrack
zypper95%
bkcrack 1.8.1-1.5
Crack legacy zip encryption with Biham and Kocher's known plaintext attack
https://github.com/kimci86/bkcrack/
sudo zypper install bkcrack- License: Zlib
- Category: Unspecified
- Architecture: x86_64
- Source Package: bkcrack
- 3 dependencies
- 1 provides
- normalized package name match
- Matched by: Bkcrack
source trail
Generated from repository data
This page is generated by av-web from the private package SQLite artifact built by scripts/generate-pkg-sqlite.py.
Combined YAML source
View the package source record on GitHub.
Used sources
- Geiger risk classifier
- cross-ecosystem install command graph
- curated package history
- external package-manager database matches
- pkg.so package database
- pkgdb category and tag curation