3 ms·
That's how maths works. Hashes are trivially reversible, all it takes is time, no miracle needed. Oracles in complexity theory are a bread and butter concept
by ithinkso 5y ago
That's how maths works. Hashes are trivially reversible, all it takes is time, no miracle needed.
Oracles in complexity theory are a bread and butter concept
- pjbeam 5y agoIf two different x can produce the same y information is lost on the hash transformation. Finding _an x_ for your y is not the same as finding _the x_. That said, Laplace's Demon is, well, a demon. Presumably the devil can get the demon to unspool time to see what the input was and the math doesn't matter, collisions or not.
- ithinkso 5y agoIn cryptography either you only need 'an x', in cases that the original x does not matter, or if it does, then you can just as easily find all x of size less than large enough N and find 'the x', it is still solely restricted by time. Laplace's demon, information loss, Landauer's principle etc. are at most tangentially related to the problem discussed
- pjbeam 5y agoYou understand that isn't the same mathematically as reversing the hash? If you farm the set of all possible x and try them to see what works you do not have an inverse function in your hands.
- ithinkso 5y ago> If you farm the set of all possible x and try them to see what works you do not have an inverse function in your hands. I'm not sure I follow, what do I have then? Could you give me an example?
- Sebb767 5y ago> Finding _an x_ for your y is not the same as finding _the x_. Not in all cases, but in the case of NFTs and other cryptocurrencies, it is. If a second private key fulfills all constraints of the original one (like size and all computed results so far), it is functionally equivalent to the original one.
- alangibson 5y agoIf hashes were trivially reversible, there'd be no cryptography. You're thinking of something like a rainbow table. Definitely not the same thing as rewinding a function that loses information.