CSS 430: PGP Encryption

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¨ Import Public Key for CSS430: on our 320 linux machine do this:

gpg --import ~css430/CSS430PubKey/CSS430.PubKey

notice to follow upper/lower case. Also, notice gpg expects two dashes (“-“) when specifying commands.

¨ To list the keys you have: do this:

gpg --list-keys

¨ To delete keys: do this:

gpg --delete-secret-and-public-keys CSS430

¨ To encrypt: follow the instruction on creating tar files with 644 permission. Assuming your tar file is: MMouse.tar, do this:

gpg –ea –r CSS430 MMouse.tar

When asked, (mumble jumble about not sure who owns this key) if you should use this key anyway? Answer yes. Once again, notice “CSS430” has capital “CSS”. In this case, the “-ea” and “-r” are options, and only one dash is required. The above command says to encrypt MMouse.tar into ASCII using “CSS430”’s public key. After the above command, you should have a file: MMouse.tar.asc in your current working directory. Submit the .asc file.

¨ Key creation: Here is the link to my help file for creation of the key.

¨ Verification: optional If you are concerned that something may have gone wrong in your encryption procedure, here is what you can do: The following procedure is optional, you _do not_ have to do follow, but if you are concerned, this is what you can do:

a. Create your own private key: follow the above Key Creation instruction to create your own pgp key.

b. Encrypt this way:

gpg –ea –r CSS430 –r <your login name> -s MMouse.tar

Notice the above encryption options says encryption with two keys (yours and CSS430’s). Now you can decrypt by typing: with your passphrase

gpg MMouse.tar.asc

Since you specified –r CSS430 in the encryption, I will still be able to decrypt your submission.

¨ More Information: As always, on unix-based system, do a:

man gpg

to find out more information on the command, or do:

gpg –help

and see what you get.