GnuPG 101
Import GPG private key to another computer
gpg --import private.asc
is the command to import the GnuPG private key onto another computer.
vinay@goodachari:~/Documents$ gpg --import private.asc
gpg: directory '/home/vinay/.gnupg' created
gpg: keybox '/home/vinay/.gnupg/pubring.kbx' created
gpg: /home/vinay/.gnupg/trustdb.gpg: trustdb created
gpg: key D3FDE3D93A1FCF50: public key "Vinay Keshava <vinaykeshava@disroot.org>" imported
gpg: key D3FDE3D93A1FCF50: secret key imported
gpg: Total number processed: 1
gpg: imported: 1
gpg: secret keys read: 1
gpg: secret keys imported: 1
Now edit the imported key and trust the key ultimate
ly.
vinay@goodachari:~/Documents$ gpg --edit-key D3FDE3D93A1FCF50 trust quit
gpg (GnuPG) 2.2.40; Copyright (C) 2022 g10 Code GmbH
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
ssb cv25519/FD6F2858DED47C32
created: 2022-11-25 expires: never usage: E
[ unknown] (1). Vinay Keshava <vinaykeshava@disroot.org>
sec ed25519/D3FDE3D93A1FCF50
created: 2022-11-25 expires: never usage: SC
trust: unknown validity: unknown
ssb cv25519/FD6F2858DED47C32
created: 2022-11-25 expires: never usage: E
[ unknown] (1). Vinay Keshava <vinaykeshava@disroot.org>
Please decide how far you trust this user to correctly verify other users' keys
(by looking at passports, checking fingerprints from different sources, etc.)
1 = I don't know or won't say
2 = I do NOT trust
3 = I trust marginally
4 = I trust fully
5 = I trust ultimately
m = back to the main menu
Your decision? 5
Do you really want to set this key to ultimate trust? (y/N) y
sec ed25519/D3FDE3D93A1FCF50
created: 2022-11-25 expires: never usage: SC
trust: ultimate validity: unknown
ssb cv25519/FD6F2858DED47C32
created: 2022-11-25 expires: never usage: E
[ unknown] (1). Vinay Keshava <vinaykeshava@disroot.org>
Please note that the shown key validity is not necessarily correct
unless you restart the program.
vinay@goodachari:~/Documents$ gpg --list-keys
gpg: checking the trustdb
gpg: marginals needed: 3 completes needed: 1 trust model: pgp
gpg: depth: 0 valid: 1 signed: 0 trust: 0-, 0q, 0n, 0m, 0f, 1u
/home/vinay/.gnupg/pubring.kbx
------------------------------
pub ed25519 2022-11-25 [SC]
2F7E32FC9C01622BC797E60AD3FDE3D93A1FCF50
uid [ultimate] Vinay Keshava <vinaykeshava@disroot.org>
sub cv25519 2022-11-25 [E]
And upon the listing the GnuPG keys present, the imported key with new level ultimate trust is displayed.