Slashdot Mirror

← Back to Stories (view on slashdot.org)

Practical Exploits of Broken MD5 Algorithm

Posted by CowboyNeal on from the as-news-breaks-so-does-encryption dept.

jose parinas writes "A practical sample of an MD5 exploit can be found, with source code included,in codeproject, a site for .Net programmers. The intent of the demos is to demonstrate a very specific type of attack that exploits the inherent trust of an MD5 hash. It's sort of a semi-social engineering attack. At Microsoft, the MD5 hash functions are banned. The main problem is that the attack is directed to the distribution of software process, as you can understand reading the paper, Considered Harmful Someday. Some open source programs, like RPM, use MD5, and in many open source distributions MD5 is used as check sum."

2 of 253 comments (clear)

  1. Re:H(x) == H(y) - H(x + q) == H(y + q) ? by Ckwop · · Score: 5, Interesting

    Is this true for other popular hash functions?


    No it is not. The newer hashes, such as Whirlpool, do not have this problem. You're correct in saying this is a "well known result" and every cryptographer worth his salt says that this fact constitutes a break of the algorithm. We've known since the middle of the nineties that breaking MD5 was within reach. The fact there has been so much inertia in getting people to change is quite incredible really.


    At Toorcon this year, Dan Kaminsky showed a way to create two different webpages that render properly in a browser but have the same MD5 hash. Anybody who thinks this attack is theortical and ignorable is grossly mistaken.


    Simon


  2. Yadda Yadda by Effugas · · Score: 5, Interesting

    Two pages, same hashes, etc. (This is the guy who wrote the MD5 someday paper.)

    http://www.doxpara.com/t1.html
    http://www.doxpara.com/t2.html