Codebusters Test Codebusters Cryptography Theory and History 4

Question 1

Who is known as the 'father of the NSA' and made seminal contributions to information theory and cryptography?

Accepted Answer

Claude Shannon

Answer

Claude Shannon's 1949 paper 'Communication Theory of Secrecy Systems' founded modern cryptography as a mathematical science.

Question 2

The Diffie-Hellman key exchange, published in 1976, introduced which revolutionary concept to cryptography?

Accepted Answer

Public-key (asymmetric) cryptography

Answer

Diffie and Hellman's paper introduced public-key cryptography, allowing two parties to exchange keys securely over an insecure channel.

Question 3

During World War II, the Allied codebreakers at Bletchley Park who broke ENIGMA were led by which mathematician?

Accepted Answer

Alan Turing

Answer

Alan Turing led key efforts at Bletchley Park and designed the 'Bombe' machine used to crack ENIGMA cipher traffic.

Question 4

The Caesar cipher is an example of which specific cipher type?

Accepted Answer

ROT cipher / shift cipher

Answer

The Caesar cipher shifts each letter by a fixed number of positions, making it a rotation (ROT) or shift cipher.

Question 5

The Atbash cipher, originating in Hebrew tradition, works by:

Accepted Answer

Mapping each letter to its mirror image in the alphabet (A↔Z, B↔Y, etc.)

Answer

Atbash substitutes the first letter of the alphabet for the last, the second for the second-to-last, and so on.

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