Police have been inspecting a crime scene that they were called into, during their investigation they found a USB stick that belongs to the suspect. Police believe the USB stick contains an important message that will help them solve the case and impersonate the criminal. The suspect used encryption to encrypt his address which was in all documents found. E-crime department had to decrypt the message, upon inspecting the USB Stick police found the following message: DJOCIT WWDN TYWTNAPRP BBMV SIWRVHCUTO. It is believed that before the incident, the suspect enrolled in online courses to learn Caesar cipher, another substitution with multiple shifts (keys) and the one-time pad. Police believe they have the one time pad key found on a piece of paper in the crime scene as well as some other notes about another method of substitution but the notes aren’t clear, the one-time pad Key was:
5,7,3,10,9,14,12,8,1,4,6,3,5,9,14,2,5,10,7,4,6,7,12,9,3,5,2,11,13,4,2,5,7 and police believe the
other substitution could either be 567 or 234 based on his notes . You are required to decrypt the message and find the suspect’s address.
one time pad is for transposition cypher
Answers
Answered by
1
Answer:
Explanation:
Step 1:
In this we will use Vernal Cipher, because it has one-time padding with a 30 key length.
Decryption is step used in one-time padding for ordering with a different key , since the page will be destroyed once its been used.
Cipher text - number conversion
convert with 26 mod:
4,13,17,8,4,14,4,23,23,10,9,2,12,22,4,20,10,14,25,14,18,3,13,17,2,26,13,25,13,13
Step 2: Decryption with 567 mod 25,7,10,3,24,7,25,17,16,5,3,21,7,16,23,15,4,7,20,8,11,24,7,10,23,16,6,20,7,6
Step 3: On cipher substitution, letters will be moved to other places.
Shift with 1
Shift with 2
Shift with 3
And the final outcomes will be WE HAVE WON CASE NUMBER FIVEHUNDRED
Similar questions