GnuPG
GnuPG (GPG) is a free implementation of the OpenPGP standard for encrypting and signing data and communications.
Legal & ethical use. Use this tool only on systems, networks and data that you own or have explicit written permission to test. Unauthorised access or scanning can break computer-misuse laws (for example Pakistan's Prevention of Electronic Crimes Act, 2016, and equivalents elsewhere). Practise in your own lab or in authorised environments such as CTFs.
What it is used for
- Verify the signature of a downloaded file
- Encrypt a file for a specific recipient
Key features
- Public-key encryption
- Digital signatures
- Key management
Installation
Preinstalled on many Linux systems; Windows/macOS packages are listed on gnupg.org/download.
Beginner usage guide
Generate a key pair, export your public key, and practise signing and verifying a test file.
Example commands
Run these only against your own lab or authorised targets. Placeholder addresses such as 192.0.2.x are documentation ranges.
Generate a key pair
gpg --full-generate-keyInteractive prompts choose the key type, size and expiry.
Verify a detached signature
gpg --verify file.tar.gz.sig file.tar.gzChecks that the file matches the signature made by the signer's key (import their public key first).
References
Source verification
Last reviewed: 2026-10-27
Links checked over HTTP: 2026-10-27 07:51 UTC — official: 200, docs: 200, repo: 200
Command flags checked against the real binary gpg (gpg (GnuPG) 2.4.9) on 2026-10-27.