Codebusters Test Codebusters Transposition Ciphers 3

Question 1

What distinguishes the Myszkowski transposition from standard columnar transposition?

Accepted Answer

Repeated letters in the keyword cause their columns to be combined and read together left to right before moving to the next rank

Answer

In Myszkowski transposition, when the keyword contains repeated letters, all columns sharing the same key letter are read out together (left to right across those columns) before advancing to columns with the next-ranked letter.

Question 2

How does a turning grille cipher work?

Accepted Answer

A card with cut-out holes is placed over paper; the holes are filled, the card is rotated 90°, holes filled again — repeated four times to fill the grid

Answer

A turning grille uses a square card with holes cut so that rotating it 90° at a time exposes every cell of the underlying grid exactly once across four positions, allowing the message to be hidden within a block of text.

Question 3

Which of the following is the strongest attack strategy against a single columnar transposition with an unknown keyword?

Accepted Answer

Anagram the columns by testing column orderings that produce the best English digraph scores between adjacent column pairs

Answer

Column anagramming — testing reorderings of ciphertext columns by scoring how well adjacent column pairs match English digraph frequencies — is the standard and most effective attack on single columnar transposition.

Question 4

Which of the following is correctly classified as a transposition cipher rather than a substitution cipher?

Accepted Answer

Rail fence cipher

Answer

The rail fence cipher rearranges the positions of plaintext letters without changing the letters themselves, making it a transposition cipher; Vigenère, Caesar, and Atbash all replace letters with different letters.

Question 5

In a Codebusters competition, if a transposition ciphertext has 30 letters and you suspect columnar transposition with a 5-letter keyword, how many rows does the grid have?

Accepted Answer

6 rows

Answer

With 30 letters and 5 columns (keyword length 5), 30 ÷ 5 = 6, so the grid has exactly 6 complete rows with no incomplete last row.

Codebusters Test Practice Test

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Codebusters Test Codebusters Transposition Ciphers 3