Furutsuki https://blog.hatena.ne.jp/Furutsuki/ ふるつき https://furutsuki.hatenablog.com/ SECCON Beginners CTF 2025のCrypto問題のwriteupです。 seesaw 01-Translator elliptic4b Golden Ticket mathmyth seesaw import os from Crypto.Util.number import getPrime FLAG = os.getenv("FLAG", "ctf4b{dummy_flag}").encode() m = int.from_bytes(FLAG, 'big') p = getPrime(512) q = getPrime(16) n = p * q e = 65537 … 190 <iframe src="https://hatenablog-parts.com/embed?url=https%3A%2F%2Ffurutsuki.hatenablog.com%2Fentry%2F2025%2F07%2F27%2F223211" title="SECCON Beginners CTF 2025 writeup - ふるつき" class="embed-card embed-blogcard" scrolling="no" frameborder="0" style="display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;"></iframe> https://cdn-ak.f.st-hatena.com/images/fotolife/F/Furutsuki/20250727/20250727210338.png Hatena Blog https://hatena.blog 2025-07-27 22:32:11 rich https://furutsuki.hatenablog.com/entry/2025/07/27/223211 1.0 100%