[Resolved] Md5

[Megahertza]

I'm using a flat file database right now and Someone suggested using md5 encyrption to keep passwords safe, I've check the manual and I know how change a string into a md5 string.

Can i change a MD5 string back into a non encrypted sting?

<?php
$string = "password";
echo md5($string);
?>

md5($string) => $string

[Installer]

md5 isn't encryption. An md5 string can represent more than one original string. So you can convert it, but then it's guesswork as to whether you have the original string you want or not (and at a high cost of processing power).

[Megahertza]

thanks man

[czambran]

HUH!!!

An md5 string can represent more than one original string.

I heard that somebody discover a colission on md5 but from that to say that it can represent more than one original string is a little far fetch(Just 1 collision has been discovered so far). It is theoretically(guess is real now since somebody found a collision) possible that two strings will give u the same hash but is quite unlikely.

[Installer]

"md5()" returns a 16- or 32-character string, no matter the length of the input string. How are you going to hash any given string of 33 characters without reuse? There's no limit, afaik, to the input string length. Also, look at the suggestion by "martin" on the md5 manual page.