https://n9o.xyz/tags/crypto/ Recent content in Crypto on Hugo -- gohugo.io en © 2026 Vaishnav Baraskar Mon, 14 Jul 2025 00:00:00 +0000 https://n9o.xyz/capturetheflag/blindspot/ Mon, 14 Jul 2025 00:00:00 +0000 https://n9o.xyz/capturetheflag/blindspot/ <h2 class="relative group">0x00 – Prologue <div id="0x00--prologue" class="anchor"></div> <span class="absolute top-0 w-6 transition-opacity opacity-0 ltr:-left-6 rtl:-right-6 not-prose group-hover:opacity-100"> <a class="group-hover:text-primary-300 dark:group-hover:text-neutral-700 !no-underline" href="#0x00--prologue" aria-label="Anchor">#</a> </span> </h2> <p>I saw &ldquo;ECDSA nonce reuse&rdquo; and knew we were about to crack something open real clean. When you’re dealing with ECDSA, one reused <code>k</code> is all it takes to rip the private key wide open. It’s not about breaking the algorithm—it’s about catching the dev slipping. And they slipped.</p> https://n9o.xyz/capturetheflag/binarybandlands/ Sun, 21 Apr 2024 00:00:00 +0000 https://n9o.xyz/capturetheflag/binarybandlands/ <h2 class="relative group">0x00 – Prologue <div id="0x00--prologue" class="anchor"></div> <span class="absolute top-0 w-6 transition-opacity opacity-0 ltr:-left-6 rtl:-right-6 not-prose group-hover:opacity-100"> <a class="group-hover:text-primary-300 dark:group-hover:text-neutral-700 !no-underline" href="#0x00--prologue" aria-label="Anchor">#</a> </span> </h2> <p>I knew from the moment I saw &ldquo;MD5&rdquo; in the challenge description, things were about to get weird. Anyone who&rsquo;s spent enough time around outdated crypto knows MD5 is a landmine. It’s fast, broken, and predictable in just the right (or wrong) ways. This challenge leaned all the way into that mess.</p> https://n9o.xyz/capturetheflag/zkpof/ Sat, 09 Mar 2024 00:00:00 +0000 https://n9o.xyz/capturetheflag/zkpof/ <h2 class="relative group">0x00 – Prologue <div id="0x00--prologue" class="anchor"></div> <span class="absolute top-0 w-6 transition-opacity opacity-0 ltr:-left-6 rtl:-right-6 not-prose group-hover:opacity-100"> <a class="group-hover:text-primary-300 dark:group-hover:text-neutral-700 !no-underline" href="#0x00--prologue" aria-label="Anchor">#</a> </span> </h2> <p>There are some challenges that punch you in the face with math. And then there are ones like this—&ldquo;ZKPoF&rdquo;—that slowly pull you in, pretending to be a protocol puzzle, until you realize Python’s <code>int()</code> is about to be your best friend and worst enemy. This was a zero-knowledge proof challenge… but with a twist. Instead of proving knowledge of a secret, I was exploiting the protocol for leaking just enough of it to reconstruct the whole damn secret.</p> https://n9o.xyz/capturetheflag/encryptedmail/ Sat, 02 Sep 2023 00:00:00 +0000 https://n9o.xyz/capturetheflag/encryptedmail/ <p>0x00 – Prologue</p> <p>This one was different. Not just some base64 puzzle or random math CTF fluff. It had structure. It had depth. I knew from the first glance that &ldquo;Encrypted Mail&rdquo; was hiding something sophisticated. There was a Zero-Knowledge Proof involved — that alone made me crack my knuckles. That phrase isn’t tossed around unless it means business.</p> https://n9o.xyz/capturetheflag/nahamcon/ Sun, 07 May 2023 00:00:00 +0000 https://n9o.xyz/capturetheflag/nahamcon/ <h2 class="relative group">0x00 – Prologue <div id="0x00--prologue" class="anchor"></div> <span class="absolute top-0 w-6 transition-opacity opacity-0 ltr:-left-6 rtl:-right-6 not-prose group-hover:opacity-100"> <a class="group-hover:text-primary-300 dark:group-hover:text-neutral-700 !no-underline" href="#0x00--prologue" aria-label="Anchor">#</a> </span> </h2> <p>Sometimes a CTF throws everything at you: logic bugs, broken binaries, half-documented APIs, and the occasional ancient Star Wars meme. NahamCon 2023 was that kind of ride. Our team, SneakBytes, dove in headfirst and came out the other side with a trail of solved challenges, caffeinated brains, and some solid lessons.</p>