Do you have any idea how rainbow tables actually work and what it would take to "create" one for the SHA-256 hash used by Bitcoin mining? In order to create suc

Do you have any idea how rainbow tables actually work and what it would take to "create" one for the SHA-256 hash used by Bitcoin mining? In order to create such a rainbow table, you would have to do about 2^256 SHA-256 computations. All of the Bitcoin mining ever done so far has carried out somewhere in the order of 2^87. To put this in perspective, the most power-efficient miners available right now require 0.1 J/GH of energy. There are roughly 10^24 stars in the visible universe putting out about 10^27 watts each. If you could use the entire energy output of all those stars to mine Bitcoins with the most efficient mining hardware currently available for the entire lifespan of the universe to the present day, you'd still get less than 2^210 hashes, about 1/10^74th of what you'd need to create a rainbow table for SHA-256. I'm pretty sure that even upgrading this hypothetical universe-wide computational machinery to hypothetical mining hardware that's as efficient as the laws of thermodynamics allow wouldn't get you close.