I need help with a practice problem for an upcoming test. I've learned the answer to the problem is "well done", but don't know how to get there. Any help is greatly appreciated.
Suppose that the RSA modulus of $n := 42313421$ used with an encryption exponent of $2015$ produces the pair $(27285537, 25251845)$ of ciphertexts. Use the fact that
$26437093^2 ≡ 1 \pmod n$
to find the original plaintext message. Show your work.
I don't see how fact stated helps with the problem.