I heard about RSA, so I took a go at implementing it.
We are given secure.txt, which are RSA parameters.
Running yafu on n, we see that n is p^2 where p is a large prime.
The solution is pretty simple, since phi(p^2)=(p-1)p when p is prime, and we simply calculate ed=1(mod p(p-1)) and m=pow(c,d,n).
Flag:
hsctf{square_number_time}