Foreword First ever CTF. Managed to solve a few challenges and learnt a ton! Challenges Baby The message is encrypted using the textbook RSA algorithm, and to decrypt the message we need to retrieve the values of the two primes p and q. We know the value of $r \times p - s \times q$, let the value be a. We have this observation that $r > s$, and $a < 0$, hence $p < q$.