[Cryptography] SHA-256 decrypted (8 rounds)

[Ron Garret]

> On Apr 5, 2024, at 8:27 PM, zeb--- via cryptography <cryptography at metzdowd.com> wrote:
> 
> Terminology be damned; was the original challenge (full-fledged premage that matches output hash deb360ae3c1ff7a29f83731b33dcd4bf354a5e80de2dc50370ebf55a14216b85) fulfilled or not?

Not.

> And if not, precisely why is Mr McDair's "examples" not enough?

Because they don't have a sha256 hash of deb360ae3c1ff7a29f83731b33dcd4bf354a5e80de2dc50370ebf55a14216b85.  At best they produce that value after a limited number of rounds (i didn't actually check) but that is not the challenge.  (BTW, it is easily seen that McDair's examples are almost certainly not fulfillments of Ray's challenge simpy because he gives more than one example.  If all of those examples were in fact fulfillments of Ray's challenge then not only would he have found a sha256 preimage, he would have found a *collision*, and that would be Big News.)

Editorial comment: the fact that you would ask whether or not the challenge was fulfilled indicates that you are seriously entertaining the possibility that McDair may have produced a new result here.  While I can't rule that out entirely, from where I sit, having followed this exchange only casually, McDair exhibits all the hallmarks of a charlatan.  He uses terminology in a non-standard way, conflating hashing and encryption.  He places a great deal of emphasis on irrelevant details, like the fact that his examples use text from the bitcoin paper.  He makes a big deal out of attacking 17 rounds of sha256 when a 45-round attack has been publicly known since 2011 [1].

So while it's possible that there is a pony buried underneath the BS that one might unearth with sufficient diligence, I'll give long odds against.

rg

[1] https://eprint.iacr.org/2011/286.pdf <https://eprint.iacr.org/2011/286.pdf>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://www.metzdowd.com/pipermail/cryptography/attachments/20240406/a5633395/attachment.htm>