{"type":"rich","author_url":"https://blog.hatena.ne.jp/M5453/","published":"2025-06-24 22:52:49","blog_url":"https://m5453.hatenablog.com/","blog_title":"Learning cyber security by playing and enjoying CTFs","categories":[],"provider_url":"https://hatena.blog","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fm5453.hatenablog.com%2Fentry%2F2025%2F06%2F24%2F225249\" title=\"IERAE CTF 2025 &quot;Cubic Math&quot; upsolve - Learning cyber security by playing and enjoying CTFs\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","height":"190","image_url":null,"title":"IERAE CTF 2025 \"Cubic Math\" upsolve","author_name":"M5453","width":"100%","provider_name":"Hatena Blog","url":"https://m5453.hatenablog.com/entry/2025/06/24/225249","description":"\u5272\u308a\u8fbc\u307f\u5fa1\u514d\uff01 IERAE CTF 2025 \u306e Crypto \u30dc\u30b9\u554f\u984c\"Cubic Math\"\u3067\u3059\u304c\u3001\u3069\u3046\u306b\u304b upsolve \u53f6\u3044\u307e\u3057\u305f\u3002 \u57f7\u7b46\u4e2d\u306e writeup \u3092\u307b\u3063\u305f\u3089\u304b\u3057\u3066\u3001\u3053\u3061\u3089\u3092\u512a\u5148\u3057\u3066\u3057\u307e\u3063\u305f\u7f6a\u3092\u304a\u8a31\u3057\u304f\u3060\u3055\u3044\u3002 \u8a2d\u554f It's a very very fun math time! nc \uff1credacted\uff1e \u30b5\u30fc\u30d0\u30b9\u30af\u30ea\u30d7\u30c8\u306f\u4ee5\u4e0b\u3067\u3059\u3002 \u300cserver.sage\u300d with open(\"flag.txt\", \"r\") as f: FLAG = f.read() secret = randrange(2**256) primes = [] p = secret while \u2026","version":"1.0"}