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Start using PGP

Why do you need PGP? - by Phil Zimmerman (dutch version)

PGP section in cryptoparty handbook - Chapter 6 Email Encryption


More education: tips, video & podcast: //


  • Thunderbird with enigmail - graphical use interface, easy to use
  • GPG command line client - easy to use if you prefer commandline stuff
  • Kleopatra - slowwwww, deinstalled it
  • ...

Level of safety

  • The encrypted message/file is considered safe
    • if your private key isn't compromised (duh)
    • and given that your key is strong enough
  • PGP is not anonymous
    • Sender and receiver IDs are known. Including names if the keys are uploaded to key servers
  • Signing keys of your friends
    • Pro: build a web of trust
    • Con: everyone can see your network


  • phicoh
    • gpg1.4 and nmh. Nmh is a command line mail clinet. Some script integrating nmh and gpg can be found at
      • it lacks the possibility to reply on a pgp encrypted mail

How to replace your current key with a stronger one

Narya: this was something I couldn't find easily, so therefore I post it here.

I had generated a new stronger key with Thunderbird/enigmail. Choosing which key to use from the commandline is easy (flag -u YOURPGPID). My Thunderbird client, however, had switched completely to the new key. I actually wanted to send around an e-mail with my new key first, signed by my old key. Couldn't find the right option in Thunderbird anywhere. This is how it was solved (quite easy, but you need to know where to look):

  • Close Thunderbird
  • Make a backup of ~/.thunderbird/some-code-here/prefs.js
  • Search in the prefs.js file for "pgpkeyId" and change the identifier into the identifier of the key you want to use
  • Start Thunderbird, et voila
  • Sign your new key with your old key
  • Now you can send a signed e-mail (signed with your old key) to your friends with your new public key, do the above again, fill in your new identifier... and live happily ever after

More command line tips

How to add second email address to your key

How to export your key to key-servers

to push your keyring changes to the key server.

$ gpg --keyserver --send-key xyxyxyxy

To test if it's there:

How to add another person's key from the server if i trust them

  • to make it easier, search for their key from one of the key servers : or
gpg --keyserver --search $USER

How to add another person's key from the file

gpg --import public.key

Encrypt & send from the terminal

gpg --recipient --encrypt testfile.txt 
(makes testfile.txt.gpg)

Decrypt on the terminal

gpg -d $FILENAME

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