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

JavaScript Language , JavaScript is "Object Oriented" like C++ or Java. (No...

JavaScript is "Object Oriented" like C++ or Java. (Note that Java and JavaScript are not the same language, which is a common misconception) It also has variables, which makes Java

Small perl program, 1. use a small perl program and matching config file to...

1. use a small perl program and matching config file to retrieve and reformat the system time for a number of remote machines via snmp.  Readings should have a local timestamp for

Shell script to find a particular pattern from the file, Normal 0 ...

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

Modularity, Modularity, Abstraction, and Modelling Whether proving a t...

Modularity, Abstraction, and Modelling Whether proving a theorem by creating up from lemmas to simple basic theorems to more accurate results, or designing a circuit by creati

Define the if statement - computer programming, Define the The if statement...

Define the The if statement - Computer Programming? The if statement is an influential selection statement and is used to control the flow of execution of statements. One of th

Reader-writer problem, The reader-writer problem can be stated as follows: ...

The reader-writer problem can be stated as follows: A shared memory location can be concurrently read by any number of tasks, but when a task must write to the shared memory locati

Design entry using the graphical editor, In this activity, you are going to...

In this activity, you are going to place components on a sheet and connect them with virtual wires to create a simple digital circuit. You will simulate the circuit to verify the c

Fileless document and encryption(stegnography), code for using tree view co...

code for using tree view control and fill it with database using asp.net and language vb.net

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