Codebusters Test Codebusters Pattern Recognition 3

Question 1

In a Xenocrypt (Spanish-language Aristocrat), which letter is typically the most frequent in the ciphertext?

Accepted Answer

E

Answer

Q

Answer

W

Answer

K

Question 2

A 3-letter ciphertext sequence 'MNK' appears 8 times in a 200-character message. What should you suspect it represents?

Accepted Answer

THE

Answer

AND

Answer

FOR

Answer

HIS

Question 3

When testing Caesar shifts, shift 4 gives 'BUX' and shift 23 gives 'CVC'. Which is more likely a correct decode?

Accepted Answer

Shift 23, because CVC is a valid consonant-vowel-consonant syllable pattern

Answer

Shift 4, because BUX contains a vowel

Answer

Shift 13 (ROT13) is always correct

Answer

Both are equally likely

Question 4

In an Aristocrat, you know ciphertext Z=T and ciphertext T=E. A ciphertext word reads 'ZT'. What does it decode to?

Accepted Answer

TE

Answer

ET

Answer

AT

Answer

IT

Question 5

In a K1 alphabet cipher with keyword 'MATH', what letter does ciphertext 'A' (second cipher position) decode to?

Accepted Answer

B

Answer

A

Answer

M

Answer

T

Question 6

A 6-letter ciphertext word has pattern ABCABD (positions 1 and 4 share a letter). Which English word fits this pattern?

Accepted Answer

REFERS

Answer

SIMPLE

Answer

BRIDGE

Answer

SMOOTH

Question 7

Which word pattern would you expect most often at the START of a ciphertext sentence in an Aristocrat?

Accepted Answer

A 3-letter high-frequency group matching THE

Answer

A 5-letter group matching ABOUT

Answer

A 2-letter group matching IT

Answer

A 4-letter group matching THEM