Introduction and History of Cryptography ECES Practice Questions (Page 3)

Questions 11–15

1. 11application · medium

   A professor is teaching a class on the history of cryptography and wants to contrast the contributions of Claude Shannon and Alan Turing. Which statement correctly distinguishes their work?

   • ABoth Shannon and Turing invented the one-time pad.
   • BShannon and Turing both worked on the same project at Bletchley Park.
   • CShannon broke the Enigma machine, while Turing developed information theory.
   • DShannon developed the mathematical theory of secrecy, while Turing focused on practical cryptanalysis.
   Reveal Solution Discussion Select an answer first
2. 12application · medium

   A museum curator is creating an interactive exhibit on ancient cryptography. The curator wants to include an example of a substitution cipher that uses a fixed reversal of the alphabet. Which cipher should the curator feature?

   • AScytale
   • BCaesar cipher
   • CAtbash
   • DVigenère cipher
   Reveal Solution Discussion Select an answer first
4. 13expert · hard

   A historian is writing a book on the history of cryptography and needs to accurately sequence the following developments: (A) Al-Kindi's frequency analysis, (B) Vigenère cipher, (C) Enigma machine, (D) Shannon's information theory. Which chronological order is correct?

   • AA, B, C, D
   • BD, C, B, A
   • CB, A, C, D
   • DA, C, B, D
   Reveal Solution Discussion Select an answer first
5. 14application · medium

   A security trainer is preparing a slide that shows how cryptographic methods evolved in response to new threats. The trainer wants to illustrate a major turning point where a cipher that had been considered strong for centuries was systematically broken, leading to the development of more complex ciphers. Which historical event best fits this narrative?

   • AThe successful cryptanalysis of the Vigenère cipher in the 19th century
   • BThe publication of the Caesar cipher by Julius Caesar
   • CThe use of the Enigma machine by Germany in World War II
   • DThe invention of the telegraph, which enabled rapid encrypted communication
   Reveal Solution Discussion Select an answer first
6. 15application · medium

   A security trainer is explaining to a junior analyst why the Caesar cipher is considered a weak modern encryption method. The trainer wants to illustrate the core weakness by comparing it to a modern algorithm. Which statement best captures the fundamental limitation of the Caesar cipher?

   • AIt requires a symmetric key exchange, which is impractical over the internet.
   • BIt is a polyalphabetic cipher that repeats a keyword, enabling frequency analysis.
   • CIt operates on blocks of 64 bits, making it vulnerable to modern cryptanalysis.
   • DIt uses a fixed shift that is easily brute-forced with only 25 possible keys.
   Reveal Solution Discussion Select an answer first