$ Linux Command

Packages

apt-key

Manage legacy APT trusted keys.

aptkeyrepositorydebianlegacy

Additional Notes

apt-key manages keys that APT uses to trust package repositories. It is now considered legacy on modern Debian and Ubuntu systems.

Modern repository setup should use key files in /etc/apt/keyrings or /usr/share/keyrings with signed-by=... in the repository source entry.

Syntax

apt-key [command] [arguments]

Parameters

  • command: Operation such as list, finger, add, or del.
  • arguments: Key file, key ID, or operation-specific value.

Common Commands

  • list: List trusted keys.
  • finger: Show key fingerprints.
  • add FILE: Add a key from a file. Legacy usage.
  • del KEYID: Remove a key by ID.

Examples

apt-key list

List legacy trusted keys.

apt-key finger

Show fingerprints for trusted keys.

sudo apt-key del ABCD1234

Remove a legacy key.

Practical Notes

  • Avoid adding new repositories with apt-key add on modern systems.
  • Prefer per-repository keyrings and signed-by= entries.
  • Be careful with repository keys: a trusted key can authenticate packages from repositories that use it.