Assignment 01 cs609 2022
Assignment 1 Spring 2022
Question No. 1
Encryption is a process which scrambles the data, so that it can only be read by the
authorized person. In today’s world, encryption is an integral part of information security.
This technique dates back to the Roman Empire era.
They use basic encryption techniques to encrypt their secret conversations in war days. One
of the various techniques are the Caesar Cipher Decryption algorithm.
In this method an alphabet is substituted by another alphabet placed n positions forward in
a circular manner.
Write a function in C/C++ to implement a Caesar Cipher Decryption algorithm. This
function will convert an input file containing some cipher-text (of alphabets only) into output
file of plain-text.
i. The function will take the following three arguments:
a) Two file paths (input and output)
b) One Shift variable of DWORD type
ii. Take 5 as the value of Shift
iii. Input file should be converted to plain-text file, byte-by-byte
iv. The function must ignore any error reporting messages
using namespace std;
void encryptyfunc(ifstream filename, ofstream decfilename, DWORD key=5)