Name:

class section:

  1. Using the webpage at http://www.rot13.com/, decipher the message: v yvxr purrfr . What does it say in English?
  2. (3 points) What are 3 reasons that ROT13 is a weak cipher?

  3. (2 points) What are the names of 2 symmetric ciphers which are considered to be strong?
  4. Why are foreign languages often hard to decode?
  5. What is the difference between PGP and GPG?
  6. What command will generate a pair of GPG keys
  7. In terms of GPG, what is a keyring?
  8. What command will import the instructor's public key into your keyring?
  9. (5 points) use the instructor's public key (at the URL on the board) to encrypt a message to him, and save the encrypted message in /tmp/instructor.mess.gpg. Get instructor sign off
  10. What command will encrypt a textfile?
  11. (2 points) save YOUR public key into /tmp/mypub.key, and have the instructor download and install it. Get instructor sign-off.
  12. (5 points) successfully decode the message which the instructor has encrypted for you, and saved on your machine in the file /tmp/incoming.gpg
  13. What command will decrypt a GPG-encrypted file?

    14. Extra Credit

  14. (2 points) what are the names of two public keyservers?
  15. What is the name of the double-agent who decoded Mary Queen of Scot's encoded correspondence, leading to her execution?
  16. (2 points) Why do militaries invest so much time and effort in code development and code breaking?