You can import someone's public key into your GPG keyring in a number of ways.
Suppose you have received the following key by email or see it on a webpage. (the key below is from the The Linux Kernel Archives OpenPGP Signature webpage.
-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: GnuPG v1.0.3 (GNU/Linux)
Comment: For info see http://www.gnupg.org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=SZZb
-----END PGP PUBLIC KEY BLOCK-----
- Copy and Paste
- Copy the entire block from the "BEGIN PGP PUBLIC KEY BLOCK" line to the "END PGP PUBLIC KEY BLOCK" line (get the dashes on those lines as well).
- At a shell prompt, type
gpg --import. The gpg program will start awaiting your input. - Paste the PGP key and then hit enter followed by Ctrl-D to terminate the program.
- You should then see something like the following (the email address
has been altered to preclude spam spiders picking it up).
gpg: key 517D0F0E: public key "Linux Kernel Archives Verification Key <ftpadmin@kernel69296.org>" imported
gpg: Total number processed: 1
gpg: imported: 1
- Import File
- Save the PGP public key above to a file. The file should contain the entire block from the "BEGIN PGP PUBLIC KEY BLOCK" line to the "END PGP PUBLIC KEY BLOCK" line (get the dashes on those lines as well).
- If you saved the file as ftpadmin.txt you would issue the command
gpg --import ftpadmin.txt
- Obtain from a Keyserver
- Public keys are normally available from a key server, but you
need to know which key server or key servers have the key. In
this case the key is available from wwwkeys.pgp.net, so
you could issue the command
gpg --keyserver wwwkeys.pgp.net --recv-keys 0x517D0F0Epresuming you know the key id is the hexadecimal value 517D0F0E.
- Public keys are normally available from a key server, but you
need to know which key server or key servers have the key. In
this case the key is available from wwwkeys.pgp.net, so
you could issue the command
After you have imported a key, you can verify it is on your keyring
using the command gpg --list-keys. You can delete a key
with the command gpg --delete-keys. E.g., suppose I have
the ftpadmin@kernel69296.org public key on my keyring, but wish to delete it.
I can issue the command gpg --delete-keys ftpadmin@kernel69296.org
to remove it from the public keyring. It is possible that you may have
multiple public keys for the same email address. Perhaps you have one that
is no longer used by the person to which it belongs and want to delete
that specific one. You can use the key id associated with that one,
e.g. gpg --delete-keys 517D0F0E in this case.
The key id is the sequence of numbers and letters after the slash that
you see when you list the keys on the keyring. E.g. for the
Linux Kernel Archives Verification Key, I see the following, if I
issue the command gpg --list-keys when it
is on my public keyring:
pub 1024D/517D0F0E 2000-10-10 Linux Kernel Archives Verification Key
<ftpadmin@kernel69296.org>
sub 4096g/E50A8F2A 2000-10-10
In this case, the key ID is 517D0F0E
References:
