This challenge included a hint saying, "It is recommended to use SageMath to solve this problem." There was also a link to a brief introduction to SageMath in the hints, but as I wrote on note the ...

These implementations are for demonstration purposes. They are less efficient than the implementations in the Python standard library.

This page lists "coding rules" for implementations of cryptographic operations, and more generally for operations involving secret or sensitive values. The rules on this page are general ...