Simple demonstration on using xor to encrypt data with a key, and a demonstration of an attack with both the plaintext and cyphertext

xorEncryption.c

/*
 * xorEncryption.c
 *
 *  Created on: 30 Oct 2015
 *      Author: Alex
 */
#include <stdio.h>
#include <string.h>

int main(void)
{
	char password[14] = "ABCDEFGHIJKLMN";
	char plaintext[14] = "this is secure";
	char cyphertext[14];
	char computedKey[14];

	for(int i = 0; i < 14; i++){
		cyphertext[i] = plaintext[i] ^ password[i];
	}

	printf("Encrypted data: %s\n", cyphertext);



	for(int i = 0; i < 14; i++){
		computedKey[i] = cyphertext[i] ^ plaintext[i];
	}

	printf("Key used to encrypt the data: %s\n", computedKey);

}

Output:

Encrypted data: 5**7e/4h:/(9?+
Key used to encrypt the data: ABCDEFGHIJKLMN