Simply encrypt a string in C

Question

I'm trying to encrypt a query string on a game I'm making when opening a url. It doesn't have to be complicated, in fact since I'm working from a game engine it needs to be as simple as possible. It tends to fuss if I get too low level.

I've already created the query string, I just need to take each char of it and subtract 15 from the char to lightly encrypt it. I'm just wanting to make a simple encryption that will deter most users.

I wish I could give a code example but I'm not too experienced in C, and I'm not even sure where to begin. The game engine's api usually makes everything simple for me.

Answer 1

You can do it with a very simple function:

void encrypt(char *s)
{
    int i, l = strlen(s);
    for(i = 0; i < l; i++)
        s[i] -= 15;
}

There's also a simple encryption algorithm you may be interested in, it's called XOR cipher.