Write a program to decrypt encrypted messages, Programming Languages

Assignment Help:

You are working for a cryptography department, where one of your jobs is to decipher intercepted messages that have been encrypted using a book cipher. The messages are sent by different people, each of whom writes their plaintext in a different language to confuse any attempt to decipher the messages. But this has made them a little too confident, and you have discovered a very useful secret: unaware that their messages can be cracked, each sender tends to use the same book passage over and over; all that changes is where in that passage they start the encryption. Being very lazy, they always start the encryption within 20 letters of the start of the passage. So for the purposes of this task, the 'key' is simply the starting position in the book text, and is a number from 0 to 20. Your job now is to write a computer program (a real executable program, not a spreadsheet) that can be used to decrypt these intercepted messages. The program will be required to read the ciphertext from a file and to display the plaintext on the screen, along with the key that was used to encrypt it. You will be asked to demonstrate your program to the tutor in the lab class on the due date. This is so that you will be there to run the program and make any decisions that need making. You will be given several ciphertexts to practice on, but in the demonstration you will be asked to demonstrate your program on files you have not seen. You may write your program in whatever programming language you wish.


Related Discussions:- Write a program to decrypt encrypted messages

Shell script to print pyramid, Normal 0 false false false ...

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4

C# XNA Game Development, I need help for C# XNA 2Dimension Game Development...

I need help for C# XNA 2Dimension Game Development. I am gonna send the question and my solution(incomplete). I need you to complete it. Can you help me about that. I have 6-7 days

Shell script to convert decimal no. to any other base no., Normal 0 ...

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4

Just in time compiler, Expertsmind brings you  unique  solution in java as...

Expertsmind brings you  unique  solution in java assignments Just in Time Compiler In processing, just-in-time system (JIT), also known as energetic interpretation, is a m

Design and implement instantiable classes, Overview Goals: The goals for...

Overview Goals: The goals for this assignment are Design and implement instantiable classes. Use arrays of objects. Read from and write to files. Implement basic

Java swing, Expertsmind brings you unique solution in java assignments ...

Expertsmind brings you unique solution in java assignments Swing Move is the primary Java GUI gadget tool set. It is part of Oracle's Java Groundwork Sessions (JFC) - an A

Java program, Write a program to calculate amount after n number of years b...

Write a program to calculate amount after n number of years by inputting principal at the rate of 8% interest.

Assembly language coding, i need a coding to glow 8 LEDs on a port with pwm...

i need a coding to glow 8 LEDs on a port with pwm effect

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd