The following ciphertext message, encrypted using a shift cipher, is the only cl
ID: 3628883 • Letter: T
Question
The following ciphertext message, encrypted using a shift cipher, is the only clue Mallory intercepted. In order to decipher the message and get the key, she’ll have to mount the Ciphertext Only Attack (COA). You job: write a C/C++ program to do frequency analysis to help Mallory to recover the plaintext message and the key. Hand in .cpp code and the plaintext message and key.
KWSVVSYXKSBOKRKBNRKDKXNKNBEXUKBOKDKLKBGROXDROIQODDROSBLOOBCDROIXYDSMOKPVISXOKMRWEQDROWSVVSYXKSBOZYVSDOVIKCUCDROLKBDOXNOBPYBKXYDOBLOOBDROXZBYMOONCDYCSZSDDRORKBNRKDCZSVVCYEDTECDOXYEQRDYQODBSNYPDROPVIKXNAEKPPCDROBOCDSDCXYGDRONBEXUCDEBXROCDSMUCRSCRKXNSXDYDROOOBQBKLCDROPVILIDROGSXQCKXNCRYEDCCZSDSDYEDCZSDSDYEDBOKNOBCNSQOCDPOLBEKBIDGYDRYECKXNDOX
Explanation / Answer
C/C++ program KWSVVSYXKSBOKRKBNRKDKXNKNBEXUKBOKDKLKBGROXDROIQODDROSBLOOBCDROIXYDSMOKPVISXOKMRWEQDROWSVVSYXKSBOZYVSDOVIKCUCDROLKBDOXNOBPYBKXYDOBLOOBDROXZBYMOONCDYCSZSDDRORKBNRKDCZSVVCYEDTECDOXYEQRDYQODBSNYPDROPVIKXNAEKPPCDROBOCDSDCXYGDRONBEXUCDEBXROCDSMUCRSCRKXNSXDYDROOOBQBKLCDROPVILIDROGSXQCKXNCRYEDCCZSDSDYEDCZSDSDYEDBOKNOBCNSQOCDPOLBEKBIDGYDRYECKXNDOX