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

Get back data from database by user as search, i have a database having fie...

i have a database having field name title and comm. I want to search by name and get the all data remaining title and comm(comm is integer)

Java, program take integer from user and print in alphabets

program take integer from user and print in alphabets

A Simple Distributed Computing Platform , You are asked to develop a replic...

You are asked to develop a replicator (client) that distributes a large job over a number of computers (a server group) on a single switched LAN (our BU04 lab). In this assignment,

Assembly, Write an assembly program that computes Fibonacci numbers 2-5. a....

Write an assembly program that computes Fibonacci numbers 2-5. a. Assume Fib(0)=0 and Fib(1)=1. b. Store Fib(2) in EAX, Fib(3) in EBX, Fib(4) in ECX and Fib(5) in EDX. c. Use a LOO

Python, Write a python script that will take two file names as input (src, ...

Write a python script that will take two file names as input (src, dest). Open src reading each line in the file, and replacing any occurrences of name with the string "redacted".

Simple corba program, You are working in charge of a group of programmers a...

You are working in charge of a group of programmers at a software company. Your task is to assess and research CORBA and to produce a report to be given to the programmers detailin

Explain the applet element, Explain the applet Element ? Applets are em...

Explain the applet Element ? Applets are embedded in web pages by using the and tags. The APPLET element is same to the IMG element. Like IMG APPLET references a source fil

Develop html code create web page of blue color , 1.  Develop an HTML code ...

1.  Develop an HTML code to create a Web page of blue color & display links in red color. 2.  Develop an HTML code to create a Web page which contains an image at its center.

Shell script to print the name of file that has maximum size, Normal 0 ...

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

develop a web page via href attribute, 1.  Develop a Web page via href att...

1.  Develop a Web page via href attribute of anchor tag and the attribute: vlink, alink, etc. 2.  Develop a Web page, in which when the user clicks on the link it will go to the

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