Using an affine transformation to cryptanalyze an enciphered message

Number Theory Level pending

Let \( A \rightarrow 0, B \rightarrow 1, \ldots , Z \rightarrow 25 \). \(\)

The most common letters in the English alphabet are \( E \) and \( T \), respectively.

Suppose we know that an affine transformation of the form \( a * P + b \equiv C \mod{26} \: (0 <= C <= 25) \), has been used for enciphering the enciphered message: \( USLEL \: JUTCC \: \: YRTPS \: \: URKLT \: \: YGGFV \: \: ELYUS \: \: LRYX \). \(\)

Cryptanalyze the enciphered message using the frequency of letters in the enciphered message. If \( L_{j} \) has the largest frequency and \( L_{k} \) has the second largest frequency, then let \( E \) and \( T \) correspond to \( L_{j} \) and \( L_{k} \) respectively. If \( L_{k} \) and \( L_{m} \) have the same frequency then choose one of the two, say \(L_{k} \), and determine if the message is intelligible. If not then try using \( L_{j} \) and \(L_{m} \). I constructed the problem so that the message will be intelligible, but you may have to do some guess work.

When you obtain an intelligible message, express the answer as a string of integers. List a string of the first 33 integers. \(\)

Note: The site only allows 33. \(\)

What does the message state?

×

Problem Loading...

Note Loading...

Set Loading...