SHA1 collisions proven possisble

Thu Mar 2 03:42:12 UTC 2017

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.

Nick