Question

I have two strings and I would like to mix the characters from each string into one bigger string, how can I do this in PHP? I can swap chars over but I want something more complicated since it could be guessed.

And please don’t say md5() is enough and irreversible. 🙂

$string1 = '9cb5jplgvsiedji9mi9o6a8qq1';//session_id() $string2 = '5d41402abc4b2a76b9719d911017c592';//md5() 

Thank you for any help.

EDIT: Ah sorry Rob. It would be great if there is a solution where it was just a function I could pass two strings to, and it returned a string.

The returned string must contain both of the previous strings. Not just a concatination, but the characters of each string are mingled into one bigger one.

Answer 1

If you want to make a tamper-proof string which is human readable, add a secure hash to it. MD5 is indeed falling out of favour, so try sha1. For example

$salt='secret'; $hash=sha1($string1.$string2.$salt); $separator='_'; $str=$string1.$separator.$string2.$separator.$hash; 

If you want a string which cannot be read by humans, encrypt it – check out the mcrypt extension which offers a variety of options.