note 13657 deleted from function.md5 by danbrown

Note Submitter: mbabcock-php at fibrespeed dot net ---- I must point out to all the people who read the notes this far that MD5 is _not_ encryption in a traditional sense. Creating an MD5 digest (or hash) of a message simply creates 128 bits that can be used to almost positively identify that message or object in the future. You use MD5 if you want to validate that information is true. For example, you may ask a user to submit a message through a browser POST and save an MD5 of that message in a database for a preview function. When the user submits it the second time, running the MD5 hash of the new version of the text and comparing it to the original MD5 in the database will tell you if the text has changed at all. This is how MD5 is used -- it is _not_ for encrypting things so as to get the data back afterward -- the MD5 hash version does _not_ contain the data of the original in a new form.