Re: Re: reverse MD5 ???
| From: | Jason Barnett | Date: | Mon, 13 Jun 2005 13:41:06 +0000 |
| Subject: | Re: Re: reverse MD5 ??? | ||
| References: | 1 2 3 4 5 | Groups: | php.general |
| Request: | Send a blank email to php-general+get-216885@lists.php.net to get a copy of this message | ||
Richard Lynch wrote:
On Fri, June 10, 2005 3:01 pm, Jason Barnett said:Richard, did you actually go to the site that Greg showed and look at the example? Two very different (as in content) postscript documents... same MD5 hash.That is incredibly interesting stuff, many thanks for that link! So the position seems to be that it may not be feasible to reverse MD5, but it is now feasible to create forged documents / binaries / whatever that result in exactly the same MD5 hash as the original.No.
Again I say... did you look at the other "meaningless" string in the example? I don't pretend to understand how the authors made it work, but it wasn't just some "meaningless" string that they got to match.I actually tried it out for myself... and indeed the two different documents produced the exact same MD5 sum.That's a one in a billion chance... So, if your binary file HAPPENS to match that meaningless string, you could use that OTHER meaningless string instead...
I'll bet neither of the two strings has any real-world "meaning" They just happen to be the two strings that are "easy" to find that have the same MD5. This has absolutely NO meaning in real-world uses of MD5. You'd have heard a LOT more screaming and wailing and gnashing of teeth if this mattered. :-)Unless of course most people dismiss it the same way that you seem to be dismissing it. ;) -- NEW? | http://www.catb.org/~esr/faqs/smart-questions.html STFA | http://marc.theaimsgroup.com/?l=php-general&w=2 STFM | http://php.net/manual/en/index.php STFW | http://www.google.com/search?q=php