Question

I was doing a simple c++ chat and i wanted to encrypt the messages with a simple made code.
So i thought it would be like chars a-x and then it would replace them for example a -11.
So it would need to

1. Split the message into chars
2. Change the chars into number
3. Put them back in the right order.

So does anyone knows how to do it?
Thanks 🙂

Answer 1

std::string will store arbitrary values of char, and let you access individual characters quite easily. For encryption, however, you might prefer to work with unsigned char, which is pretty easy too — std::string is just a typedef for std::basic_string<char>, but std::basic_string<unsigned char> is pretty easy to manage.

It sounds like what you want is on the order of a Ceaser cipher, though it’s easiest if you just “encrypt” everything, rather than just letters.

std::basic_string<unsigned char> s;

for (int i=0; i<s.length(); i++)
    s[i] += 5;

Then to “decrypt” you’d just do the opposite:

for (int i=0; i<s.length; i++)
    s[i] -= 5;