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GPG Tips and Tricks

Here is my public key:

-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: GnuPG v1.4.9 (GNU/Linux)
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ExECAB8CGwMGCwkIBwMCBBUCCAMDFgIBAh4BAheABQJLwfDfAAoJEBFL8He1bmsp
bZQAn06UdewDiSYXAnpTBFhze57g6fB9AKCNSIWBs9KJMH3s2ywoJKnq10UOgLkC
DQRCWT59EAgA+Wnwije843udH6aCeq450LXSra8RrS64PKHfjABxsRgYOjhuuiJO
nDaqde+i/67DFM1SoUMSxQFImGNVeOwmdCNvDUTadNt6VCbamfvFOp9uQGvyexYd
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MXeMVTb6AzB52l//gV12E+KrRcz0R2hDfdQo7XwLDLRHBdSkhEpvF3W4VdW0Fpc2
iyLBi8rtWACmzZr0IRoOzfYKgt3j9fL18wADBQgA28I2kRz8egPKzvqNZmaVey5F
DQnsJJRPc/zC8Vh7EMSYVBhchDlgepKAQN1hANqwRvGa3W6QRaMLLjvnEr+fpuiN
p3auRHSUyKBsFzo+6EiyI9Hey+5z2cwXOuwM5EL/sbTBDoppdMVwfvyQJcCckj0Z
C9Z0ylTazzwtSF1Ya5uQQDLK+cT/b9BgINdmjXydi5VeoAiJt/8T9OLeGsMfDM2i
27sDGFdHQwcdMdisuoAHeVVrmwXzz9uaINCyGywbuOrdvS3Ts1ygExycyaekg4Zv
YJfHpBW79TsLum4CtjQ7OT8HzAtEByOpaZZLjOtPGEadre3W8mTTetH8wiln2ohJ
BBgRAgAJAhsMBQJLwfDuAAoJEBFL8He1bmspx8wAn2uvVxeAyypNW0/plDHVghUn
c61aAJ4yyx5Knt/i7NkbNXGLMzjuy3R0SQ==
=Z0/D
-----END PGP PUBLIC KEY BLOCK-----

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Key Maintainence:

• gpg --armor --output alice-anderson-public-key.asc --export alice.anderson@hotmail.com
  This command will export your public key to an ASCII-armored text file. This file is then used for posting to a webpage or printing out for personal distribution.
  
  
• gpg --import bob-brown-public-key.asc
  This command will import a public key file into your keyring. Before you can use this key to encrypt, you need to sign it.
  
  
• gpg --edit-key bob.brown@hotmail.com
  This line opens up a gpg prompt for the key. From the prompt, press "fpr" to see the fingerprint. You then need to confirm that the the fingerprint of the key you just received matches what Bob Brown says it is. You should do this preferably in person, but over the phone will work too.
  
  If the fingerprints match, then sign their key with your own. Type "sign" at the prompt. It will then ask you if you are sure you want to sign this key. Press "y" here. You will be asked for your key's passphrase. Enter your passphrase, and then type "save". Now you are able to encrypt messages/documents with this person's public key.
  
  

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Encrypting and Decrypting:

• gpg --output alice-doc.gpg --encrypt --recipient bob.brown@hotmail.com alice-doc
  This command will encrypt the file "alice-doc" to "alice-doc.gpg" using Bob Brown's public key. This means that only Bob can read it.
  
  
• gpg --output bob-doc --decrypt bob-doc.gpg
  If you have been sent an encrypted document, this command will decrypt it for you, turning "bob-doc.gpg" into "bob-doc". It will ask you for your secret key's passphrase.
  
  
• gpg --decrypt bob-doc.gpg
  If you only want to see what the message looks like, you do not need the --output option. This command will decrypt and simply print to the screen.
  
  

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Signatures:

You can crytpographically 'sign' a document, thereby assuring the receiver of your document that the document came from you, and that it was not modified in transit.

• gpg --clearsign document
  This command will sign the file, but leave it unencrypted, so anybody can read it. It is useful for distributing files over the internet, in the case of downloading files from a mirror server. How do you know that the people running the mirror aren't putting viruses and harmful code in the files they are hosting for you? You sign all your files before sending them to the mirror, and then your users can check if the signature is still valid.
  
  
• gpg --output document.gpg --sign --encrypt --recipient bob.brown@hotmail.com
  You can also sign and encrypt the same document.
  
  

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Copyright © 2004 - 2024, Matthew L. Beckler, CC BY-SA 3.0
Last modified: 2010-04-11 12:03:38 PM (EDT)