reversing a hash is simply impossible and will always be impossible until the end of time
Yes. But there is another problem: it is always possible to find some preimage for any hash. RIPEMD-160 has 160 bits, secp256k1 has 256 bits, so assuming uniform distribution there are around 2^96 collisions for each address. And assuming that hash functions are regularly broken every few years, I really don't know what will be broken faster: hash functions used to generate addresses or elliptic curves.
finding a preimage is not going to help because that new message still has to be a valid public key and that adds a bigger complexity on top of such an attack. and by the way even the "broken" hash algorithms such as SHA1 are still unbroken when it comes to this type of attack. in other words we still can not find m
2 by only having h=hash(m
1) even if h is SHA1.
About 90 years ago Kurt Gödel found out, that one cannot make such "impossible" statements.
my comment was about "reversing" a hash. meaning finding message by having the hash which is simply impossible and will always be impossible because of the way hash algorithms are defined. i always like to use this example, imagine you have a very simple formula x+y=z and you know the result (z) is 10. it doesn't matter how much computing power, or what kind of crazy mathematics algorithm you use, you can never reverse x+y=10 to find x and y. there is just no way. what you can do is finding different x and y that can give same result which is the same as finding collision but not being able to reverse it.
SHA256 "solved" means cheap mining, leaving ASIC farms in the dust. One could easily mine 300 coins/day without being noticed, no need to announce anything to the big world.
that's not how bitcoin works. there is this thing called difficulty which would adjust and prevent blocks from being found too fast. on top of that if there were any kind of progress in breaking SHA256 most of the internet would be at a much bigger danger. meanwhile bitcoin simply could switch to another mining algorithm.