emcomm-tools-os-community/overlay/etc/skel/Desktop/offline/crypto/gpg-cheatsheet.md

title, date, updated, author, categories, tags, copyright

title	date	updated	author	categories	tags	copyright
GNU Privacy Guard: Crypto Cheetsheet	2026-03-19	2026-03-19	The Tech Prepper	cryptography	pgp	(C) 2026 The Tech Prepper, LLC

This is an in-progress cheatsheet for performing basic cryptographic functions using GNU Privacy Guard (gpg), including encrypting, decrypting, and verifying files in an offline environment.

List Keys

List the current keys on your system.

gpg --list-keys

• pub - Primary key
  • Your identity (root of trust)
  • Used for signing and certifying other keys
• sub - Subkey
  • Used for specific operations (usually encryption)
  • Can be replaced or rotated without changing identity
  • Can be revoked or rotated if compromised
• [SC] - Sign + Certify
• [E] - Encrypt
• unknown|full|ultimate - See "Set Trust Levels"

gpg --list-secret-keys

Create Key

gpg --full-generate-key

Encrypt File

gpg -e -r RECIPIENT file.txt

Decrypt File

gpg -d file.txt.gpg

Verify Signature

gpg --verify file.sig file.txt

gpg --verify file.asc

Set Trust Levels

Here are common trust levels for basic use:

• unknown - No trust assigned (default)
• full - You trust this person to sign other keys
• ultimate - Your own key

Perform the following steps to change the trust level for a key.

1. List the keys and identify the key ID (KEYID).

   gpg --list-keys

2. Replace KEYID with the key ID to edit.

   gpg --edit-key KEYID

3. Type trust and press [ENTER].

4. Type the number for the desired trust level and press [ENTER].

5. Type quit to exit.