nanog mailing list archives

Re: SHA1 collisions proven possisble


From: Matt Palmer <mpalmer () hezmatt org>
Date: Thu, 2 Mar 2017 14:49:12 +1100

On Thu, Mar 02, 2017 at 03:42:12AM +0000, Nick Hilliard wrote:
James DeVincentis via NANOG wrote:
On top of that, the calculations they did were for a stupidly simple
document modification in a type of document where hiding extraneous
data is easy. This will get exponentially computationally more
expensive the more data you want to mask. It took nine quintillion
computations in order to mask a background color change in a PDF.

And again, the main counter-point is being missed. Both the good and
bad documents have to be brute forced which largely defeats the
purpose. Tthose numbers of computing hours are a brute force. It may
be a simplified brute force, but still a brute force.

The hype being generated is causing management at many places to cry
exactly what Google wanted, “Wolf! Wolf!”.

The Reaction state table described in
https://valerieaurora.org/hash.html appears to be entertainingly accurate.

With particular reference to the "slashdotter" column.

- Matt


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