Instructions for exporting/importing (backup/restore) GPG keys

gpg-import-and-export-instructions.md

Every so often I have to restore my gpg keys and I'm never sure how best to do it. So, I've spent some time playing around with the various ways to export/import (backup/restore) keys.

Method 1

Backup the public and secret keyrings and trust database

cp ~/.gnupg/pubring.gpg /path/to/backups/
cp ~/.gnupg/secring.gpg /path/to/backups/
cp ~/.gnupg/trustdb.gpg /path/to/backups/
# or, instead of backing up trustdb...
gpg --export-ownertrust > chrisroos-ownertrust-gpg.txt

NOTE The GPG manual suggests exporting the ownertrust instead of backing up the trustdb, although it doesn't explain why.

Just to be sure, also follow this guide

Restore the public and secret keyrings and trust database

cp /path/to/backups/*.gpg ~/.gnupg/
# or, if you exported the ownertrust
gpg --import-ownertrust chrisroos-ownertrust-gpg.txt

Method 2

This only really works if you don't mind losing any other keys (than your own).

Export public and secret key and ownertrust

gpg -a --export chris@seagul.co.uk > chrisroos-public-gpg.key
gpg -a --export-secret-keys chris@seagul.co.uk > chrisroos-secret-gpg.key
gpg --export-ownertrust > chrisroos-ownertrust-gpg.txt

Import secret key (which contains the public key) and ownertrust

gpg --import chrisroos-secret-gpg.key
gpg --import-ownertrust chrisroos-ownertrust-gpg.txt

Method 3

This is mainly about trusting my key once I've imported it (by either restoring the pubring.gpg and secring.gpg, or by using --import). This seems to be what I do the most as I either forget to import the trustdb or ownertrust.

Ultimately trust the imported key

This is so that I can encrypt data using my public key

gpg --edit-key chris@seagul.co.uk
gpg> trust
Your decision? 5 (Ultimate trust)

NOTE If I don't trust the public key then I see the following message when trying to encrypt something with it:

gpg: <key-id>: There is no assurance this key belongs to the named user