- For some time before the development of the Vigenère cipher, “anybody sending an encrypted message had to accept that an expert enemy codebreaker might intercept and decipher their most precious secrets.” (Singh, p. 45) How is this environment different from the one that Mary Queen of Scots experienced, where one didn’t know how likely it was that one’s encrypted message was secure?
- Can you think of any ways to improve the security of the Vigenère cipher?
- The Great Cipher used by Louis XIV remained unbroken for 200 years. What were the factors that led to such a secure cipher?
- Why do you think that the advent of the telegraph motivated the use of a more secure cipher like the Vigenère cipher?
As a reminder, note that responding to these questions by leaving a comment here on the blog is one of the ways in which you can contribute to your participation grade in this course.