I was browsing Reddit yesterday when stumbled upon an interesting math problem: a user tried to implement a "smart contract" that was irredeemable under the validity of Fermat's Last Theorem.
However, the author did not account of the use of int256, leading to this solution. Thus the attacker was able to find a combination of $a, b, c, n > 2$ such that
$a^n + b^n = c^n \pmod{2^{256}}$
held true.
My questions then are:
Is Fermat's Last Theorem always invalid in finite spaces? What does this have to do with the so-called freshmen's dream?
How was the attacker able to find values of $b, c, n > 2$ so fast? I thought the difficulty of such a problem would involve tangentially the discrete logarithm assumption.