I like the footnote they attached specifically for SHA1. "[3] Google spent 6500 CPU years and 110 GPU years to convince everyone we need to stop using SHA-1 for security critical applications. Also because it was cool."
It’s also not preimage. This isn’t even a FIRST preimage attack. That table needs an additional field type: “First non-preimage deliberate crafted collision created”. However, it proves a theory that maybe with some refining *could* turn into a preimage attack. Realistically any hash function *will* have collisions when two items are specifically crafted to collide after expending insane amounts of computing power, money, and… i wonder how much in power they burned for this little stunt. > On Mar 1, 2017, at 9:42 PM, Nick Hilliard <n...@foobar.org> 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. > > Nick