https://pnasis.gitlab.io/tags/runes/ Recent content in Runes on pnasis Hugo en-us Wed, 12 Aug 2026 11:16:35 +0300 https://pnasis.gitlab.io/posts/uiuctf-2026-cryptography-writeup-rune-decryptor/ Wed, 12 Aug 2026 11:16:35 +0300 https://pnasis.gitlab.io/posts/uiuctf-2026-cryptography-writeup-rune-decryptor/ <h2 id="introduction">Introduction</h2> <p>    A few days ago, I participated in <a href="https://ctftime.org/event/3148">UIUCTF 2026</a>, a <strong>Jeopardy-style</strong> CTF competition, once again playing together with my team <a href="https://ctftime.org/team/431287">Echelon Obscura</a>. As usual, I spent a considerable amount of time looking through the reversing and cryptography challenges and one of the challenges that caught my attention was <strong>Rune Decryptor</strong>.</p> <p>    At first glance, the challenge seemed to be a relatively straightforward substitution cipher. However, after connecting to the remote service, it quickly became apparent that the substitution itself was only one part of the problem. The plaintext could be written in <strong>10 different languages</strong>, a new cipher had to be solved repeatedly and the entire process had to be completed interactively before losing the connection to the server.</p>