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

Arithmetic involving matrices, We next require taking a look at arithmetic ...

We next require taking a look at arithmetic involving matrices. We'll begin with addition and subtraction of two matrices. Therefore, assume that we have two n x m matrices, which

Program to create multithreaded calculator, Multithreaded Calculator I...

Multithreaded Calculator In this Lab, you will be implementing a simple multithreaded calculator. Our calculator will accept expressions as infix notation text strings consist

Loops, I have doubt in this section .do-while loop.could you able to clear ...

I have doubt in this section .do-while loop.could you able to clear it for me.

C, what is the c.

what is the c.

Visual basic, Lennie McPherson, proprietor of Lennie''s Bail Bonds, needs t...

Lennie McPherson, proprietor of Lennie''s Bail Bonds, needs to calculate the amount due for setting the bail. Lennie requires something of value as collateral, and his fee is 10%

Program third command line argument, Most popular news websites publish the...

Most popular news websites publish their RSS ( Really Simple Syndication ) feeds. If you haven 't heard of RSS, you may have a look at this article on Wikipedia. In this assignm

Query a SPARQL endpoint using JENA JAVA API, program the following exercise...

program the following exercises using JAVA and JENA API: SPARQL endpoint to be queried: QUERY:">http://services.data.gov.uk/education/sparql QUERY: What are the school’s names th

Calculating percentage differences-circuit diagram, In the procedure sectio...

In the procedure section, it is important to have a clear circuit diagram with component values and a brief, but accurate description of each step taken. 1. Tables for both the

Write a program that draws the initials j, Write a program that draws the i...

Write a program that draws the initials J G P on the form similar to that shown in Fig J 1 (using straight lines and curve semicircles). The figure can not have corners. All ends a

Python, please decode the following as it is answer for my assisgnment for ...

please decode the following as it is answer for my assisgnment for python: Ñò üOLOc  @ s‚ d „ Z d „ Z g Z xYe oQe ƒ e d ƒ i ƒ Z e d j oI e d

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