RITSEC CTF 2026 - Reversing Writeups (Part 2): not quite optimal

Sat, 04 Apr 2026 13:35:13 +0300

Introduction

Continuing my participation in RITSEC CTF 2026, this second part of the series focuses on another challenge from the Reversing category titled “not quite optimal”. As with the previous writeup, the goal here is to document the full thought process behind solving the challenge, from initial inspection of the binary to understanding its underlying logic and ultimately deriving the solution.

This challenge immediately gave the impression that the solution would not come from following the code literally, but rather from simplifying what the program was actually doing and stripping away unnecessary complexity.

Number Theory on pnasis

RITSEC CTF 2026 - Reversing Writeups (Part 2): not quite optimal

Introduction