Codebusters Test Graduation Requirements 3

Question 1

Which cipher graduation requirement involves encoding plaintext using a keyword where each keyword letter shifts a column of the alphabet?

Accepted Answer

Vigenere cipher

Answer

The Vigenere cipher uses a repeating keyword where each letter defines the shift applied to corresponding plaintext letters.

Question 2

For the Codebusters national trial event, teams must decode an Aristocrat WITHOUT word divisions. What is this variant called?

Accepted Answer

Patristocrat

Answer

A Patristocrat is an Aristocrat-style monoalphabetic substitution cipher presented without spaces between words.

Question 3

When decoding a Caesar cipher, a graduation requirement basic skill, what is the maximum number of shift values a student must test?

Accepted Answer

25

Answer

There are 25 possible non-zero shifts in a Caesar cipher (shifts 1 through 25), plus shift 0 which is no cipher at all.

Question 4

Which graduation requirement topic requires students to understand the Kasiski examination technique?

Accepted Answer

Finding the keyword length in a Vigenere cipher

Answer

The Kasiski examination finds repeated ciphertext sequences to determine the likely key length of a Vigenere or polyalphabetic cipher.

Question 5

In the Codebusters running key cipher, what is used as the key instead of a short repeating keyword?

Accepted Answer

A passage from a known text

Answer

A running key cipher uses a long passage from a book or known text as the key, making it non-repeating and harder to crack.

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