due: March 1.
To take the md5 or sha1 hashes of a file, you can use the commands that are already installed on any Linux box. The commands are simply, "md5sum filename", or "sha1sum filename"
Make sure that you have Thunderbird set up so that you can send and receive your TUMail. Instructions for setting up a GMail account using Thunderbird is available on Google's website.
Configure Thunderbird to use the public-private key pair that you created in part 2.
Send yourself some signed email messages. The output will look something like:
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Here's a test message. I hope that it works right. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (OpenBSD) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFHMhB63y0VT92yb/8RAjvkAJ4/qvjf+qu9WdRGTnWQd4axapCXugCgkU5a xXNQnN6IHYD2lWfcIQ4v1FI= =Xbsc -----END PGP SIGNATURE-----
Copy all files that you signed and encrypted, etc., into a directory called yourName_pgp, zip the directory, and email the zip file to the TA. Your email message should contain the link to the website where you've posted your public key, and your answers to the few questions asked. The email message must be encrypted using the TA's public key, and it should be signed.
For an unnecessary additional thrill, if you'd like to encrypt the email that you send me, you can find my public key here.
GPG is free software and it runs on Windows, Mac and many other platforms besides Linux. There are also plugins for several popular email clients, and GUI front ends so that you don't have to remember all of the commands at the command line.
It might not be a bad idea if you downloaded the software at home, and gave it a try. If you want a commercial tool which does the same thing, is probably a lot easier to use, and can even do things like encrypt entire hard drives, you could also check out this.
If you're using Ubuntu, the Thunderbird GPG Plugin is available through Ubuntu's package manager. You could also install it by downloading the appropriate XPI file.