hash - Can a neural network crack hashing algorithms? - Information Security Stack Exchange

I know that it would be computationally unfeasible. Yes, given infinite time and infinite energy, a neural net could crack SHA256. BUT (and I think this is the point @tylerl is making) because hash functions have no discernible patterns, a neural net would not be able to do any better than the naive brute-force of building a lookup table by computing the hash of every possible string. Such a lookup table would have more entries ( 2256) than there are atoms on the planet earth ( 2166) - so at least with our current level of technology it's "impossible" to hold such a table in memory or store it on any disk. Similarly, for your neural net to perform noticeably better than a dice-roll, the number of neurons you would need would probably also exceed the number of atoms on the planet.