Caesar Cipher in C and C++ [Encryption & Decryption]

Get program for caesar cypher in C and C++ for encryption and decryption.

What is Caesar Cipher?

It is one of the least difficult encryption systems in which each character in plain content is supplanted by a character some fixed number of positions down to it.

For instance, in the event that key is 3, at that point we need to supplant character by another character that is 3 situations down to it. Like A will be supplanted by D, C will be supplanted by F, etc.

For decryption simply pursue the turn around of encryption process.

Beneath I have shared program to actualize caesar cypher in C and C++.

Program for Caesar Cipher in C

Encryption

#include<stdio.h>
 
int main()
{
	char message[100], ch;
	int i, key;
	
	printf("Enter a message to encrypt: ");
	gets(message);
	printf("Enter key: ");
	scanf("%d", &key);
	
	for(i = 0; message[i] != '\0'; ++i){
		ch = message[i];
		
		if(ch >= 'a' && ch <= 'z'){
			ch = ch + key;
			
			if(ch > 'z'){
				ch = ch - 'z' + 'a' - 1;
			}
			
			message[i] = ch;
		}
		else if(ch >= 'A' && ch <= 'Z'){
			ch = ch + key;
			
			if(ch > 'Z'){
				ch = ch - 'Z' + 'A' - 1;
			}
			
			message[i] = ch;
		}
	}
	
	printf("Encrypted message: %s", message);
	
	return 0;
}

Output

Enter a message to encrypt: axzd
Enter key: 4
Encrypted message: ebdh

Decryption

#include<stdio.h>
 
int main()
{
	char message[100], ch;
	int i, key;
	
	printf("Enter a message to decrypt: ");
	gets(message);
	printf("Enter key: ");
	scanf("%d", &key);
	
	for(i = 0; message[i] != '\0'; ++i){
		ch = message[i];
		
		if(ch >= 'a' && ch <= 'z'){
			ch = ch - key;
			
			if(ch < 'a'){
				ch = ch + 'z' - 'a' + 1;
			}
			
			message[i] = ch;
		}
		else if(ch >= 'A' && ch <= 'Z'){
			ch = ch - key;
			
			if(ch < 'A'){
				ch = ch + 'Z' - 'A' + 1;
			}
			
			message[i] = ch;
		}
	}
	
	printf("Decrypted message: %s", message);
	
	return 0;
}

Output

Enter a message to decrypt: ebdh
Enter key: 4
Decrypted message: axzd

Program for Caesar Cipher in C++

Encryption

#include<iostream>
 
using namespace std;
 
int main()
{
	char message[100], ch;
	int i, key;
	
	cout << "Enter a message to encrypt: ";
	cin.getline(message, 100);
	cout << "Enter key: ";
	cin >> key;
	
	for(i = 0; message[i] != '\0'; ++i){
		ch = message[i];
		
		if(ch >= 'a' && ch <= 'z'){
			ch = ch + key;
			
			if(ch > 'z'){
				ch = ch - 'z' + 'a' - 1;
			}
			
			message[i] = ch;
		}
		else if(ch >= 'A' && ch <= 'Z'){
			ch = ch + key;
			
			if(ch > 'Z'){
				ch = ch - 'Z' + 'A' - 1;
			}
			
			message[i] = ch;
		}
	}
	
	cout << "Encrypted message: " << message;
	
	return 0;
}

Output

Enter a message to encrypt: asd zf
Enter key: 3
Encrypted message: dvg ci

Decryption

#include<iostream>
 
using namespace std;
 
int main()
{
	char message[100], ch;
	int i, key;
	
	cout << "Enter a message to decrypt: ";
	cin.getline(message, 100);
	cout << "Enter key: ";
	cin >> key;
	
	for(i = 0; message[i] != '\0'; ++i){
		ch = message[i];
		
		if(ch >= 'a' && ch <= 'z'){
			ch = ch - key;
			
			if(ch < 'a'){
				ch = ch + 'z' - 'a' + 1;
			}
			
			message[i] = ch;
		}
		else if(ch >= 'A' && ch <= 'Z'){
			ch = ch - key;
			
			if(ch > 'a'){
				ch = ch + 'Z' - 'A' + 1;
			}
			
			message[i] = ch;
		}
	}
	
	cout << "Decrypted message: " << message;
	
	return 0;
}

Output

Enter a message to decrypt: az GjK
Enter key: 2
Decrypted message: yx EhI

Remark beneath on the off chance that you have questions or discovered anything off base in the above program for caesar cypher in C and C++.