Generating GPG keys

GPG key

Overview

GPG (GNU Privacy Guard) It's a method used for encrypting and decrypting digital files and communications over the internet.

Introduction

The following document will outline how to generate one to be used for encryption of backups(duplicity) or any other use.

Pre-requisite

Ensure you have gpg installed in your machine and its version 2.1.17 or greater

gpg --version

if you not you can install it using the below on ubuntu but for other distros kindly download from GnuPG - Download

sudo apt install gnupg

Generate GPG key

gpg --full-generate-key

On the menu prompt select the default RSA and RSA (default) unless there are other explicit requirements.

Please select what kind of key you want:
   (1) RSA and RSA (default)
   (2) DSA and Elgamal
   (3) DSA (sign only)
   (4) RSA (sign only)
  (14) Existing key from card
Your selection? 1

What keysize do you want? Enter the desired or use default
Select key expiry period. Choose the desired or use default.

Please specify how long the key should be valid.
         0 = key does not expire
      <n>  = key expires in n days
      <n>w = key expires in n weeks
      <n>m = key expires in n months
      <n>y = key expires in n years
Key is valid for? (0)

Confirm your choices and press enter.

Is this correct? (y/N) y

The prompt will require you to enter the identity for your key. Enter any name must be at least 5 characters long.

GnuPG needs to construct a user ID to identify your key.

Real name: duplicity

Then enter your email address on the next prompt then enter
Then enter a comment on the next prompt then enter
Finally, confirm all your entries.

Change (N)ame, (C)omment, (E)mail or (O)kay/(Q)uit? O

You'll be presented with a password dialog, enter a secure password.

Export public key (-pub.key)

List the keys

gpg --list-keys --keyid-format SHORT
/home/morty/.gnupg/pubring.kbx
-----------------------------
pub   rsa2048/1F660965 2021-05-11 [SC]
      3775D234D1729924919064E33B10AA311F660965
uid         [ultimate] duplicity
sub   rsa2048/78876A7A 2021-05-11 [E]

NOTE: Key-ID can be in SHORT (8 last digits) or LONG (16 last digits) for the example above SHORT 1F660965, LONG 3B10AA311F660965 and then the fingerprint 3775D234D1729924919064E33B10AA311F660965

Export public key

gpg --armor --output 1F660965-pub.key --export 1F660965

Export private keys (-priv.key)

List the keys

gpg --list-secret-keys --keyid-format SHORT
/home/morty/.gnupg/pubring.kbx
-----------------------------
sec   rsa2048/1F660965 2021-05-11 [SC]
      3775D234D1729924919064E33B10AA311F660965
uid         [ultimate] duplicity
ssb   rsa2048/78876A7A 2021-05-11 [E]

Export the secret key

gpg --armor --output 1F660965-priv.key --export-secret-keys 1F660965

Export ultimate keys (-ultimate.trust)

gpg --export-ownertrust

Pick the fingerprint of your key-id from the list

6826D25B796311C5B124B2F4600AD683013E97CA:6:
3775D234D1729924919064E33B10AA311F660965:6: here!!
940358D7E31AB2F3020B3E3713BDD534C84AD974:6:

echo "3775D234D1729924919064E33B10AA311F660965:6:" >  1F660965-ultimate.trust

DONE!!

Import the key

gpg --import 1F660965-priv.key
gpg --import 1F660965-pub.key
gpg --import-ownertrust 1F660965-ulimate.trust

Delete the key

gpg --delete-secret-keys 1F660965-priv.key
gpg --delete-keys 1F660965-pub.key

Documentation