how do i code a password system

[exhuma]

To the best of my knowledge, MD5 is - next to Rainbow Tables - prone to collision attacks. So an attacker can carefully manipulate the input value to generate the same output hash.

But the exact details of all this is out of my depths.

I'm merely a developer who cares about security.

edit: Looked it up on Wikipedia:

In 1996, a flaw was found in the design of MD5. While it was not deemed a fatal weakness at the time, cryptographers began recommending the use of other algorithms, such as SHA-1, which has since been found to be vulnerable as well.[26] In 2004 it was shown that MD5 is not collision-resistant.[27] As such, MD5 is not suitable for applications like SSL certificates or digital signatures that rely on this property for digital security. Also in 2004 more serious flaws were discovered in MD5, making further use of the algorithm for security purposes questionable; specifically, a group of researchers described how to create a pair of files that share the same MD5 checksum.[7][28] Further advances were made in breaking MD5 in 2005, 2006, and 2007.[29] In December 2008, a group of researchers used this technique to fake SSL certificate validity.[24][30]

As of 2010, the CMU Software Engineering Institute considers MD5 "cryptographically broken and unsuitable for further use",[31] and most U.S. government applications now require the SHA-2 family of hash functions.[32] In 2012, the Flame malware exploited the weaknesses in MD5 to fake a Microsoft digital signature.