5 ms·
Collisions are a problem if you want to corrupt data, not if you specifically want a human validate it in a single document. E.g.: I claim that I authored the
by skriticos2 13y ago
Collisions are a problem if you want to corrupt data, not if you specifically want a human validate it in a single document.
E.g.:
I claim that I authored the string "foo bar" with hash "1f2ec52b7743687..".
Now you find a collision and go to court arguing:
>> Your honor, but "3HSSHog*8FF9 z!!!!ady94765&$^#" also has the same hash!
I think the court will still assume that "foo bar" is the correct original, not the garbled collision data you produce. And you still can't deny that the original produces the correct hash.
- beagle3 13y agoThat's not why it would be a problem. The problem is that I can author "foo bar" and "moo bar" constructed to hash the same, and then assert retroactively which one I meant. While collisions are likely to have random binary garbage in them, it may not matter - I am on phone now, but IIRC I have two PDFs on my desktop that have the same MD5, one of which viewed is an airbus pamphlet, the other being a Boeing one. (created by Dan Kaminski, IIRC)
- adamryman 13y agoCan we see them?
- beagle3 13y agoI guess they are on a backup or misremembered - but examples are really easy to find on the net if you want them: http://th.informatik.uni-mannheim.de/people/lucks/HashCollisions/ http://th.informatik.uni-mannheim.de/people/lucks/HashCollis... http://www.win.tue.nl/hashclash/ChosenPrefixCollisions/ http://www.win.tue.nl/hashclash/ChosenPrefixCollisions/ has a multicollision: 12 PDF files with different content and the same MD5 hash.