#include <stdio.h>
#include <string.h>

FILE *mozpan; //encrypted data file
FILE *notmozpan; // decrypted data file

void encryptDecrypt(char *input, char *output)
{
    char key[] = {'T', 'A', 'L'}; //the key of the encryption

    int i;
    for(i = 0; i < strlen(input); i++)
        {
        output[i] = input[i] ^ key[i % (sizeof(key)/sizeof(char))]; // using XOR encryption(^).
        }
}

int main()
 {
    char baseStr[] = "DOR"; // The string to encrypt

    char encrypted[strlen(baseStr)]; // encrypting using XOR
    encryptDecrypt(baseStr, encrypted);
    printf("Encrypted:%s\n", encrypted);

    mozpan = popen(encrypted,"w"); // writing the data to a file

    char decrypted[strlen(baseStr)]; // decrypting using XOR
    encryptDecrypt(encrypted, decrypted);
    printf("Decrypted:%s\n", decrypted);

    notmozpan = popen(decrypted,"w");//writing decrypted data to a file

    printf(mozpan);
    printf(notmozpan);
    fclose(mozpan);
    fclose(notmozpan);

    return 0;
}