1. Why might you want to encrypt a document?
2. Encryption was originally invented to protect data on electronic computers.
3. In the early 20th century, telegrams could be electro-mechanically encrypted.
4. How did weak encryption lead to the entry of the USA into the First World War?
5. In 2007 a UK Government department lost two CD-ROMs of unencrypted data in the post.
6. Substitution ciphers are vulnerable to …
7. What did Leon Battista Alberti devise in the 15th century?
8. If the length of the key can be discovered, even a polyalphabetic cipher can be vulnerable to …
9. How did the Enigma machine used in World War Two encrypt messages?
10. Today public key algorithms are usually based on …