Do you recall Notpron? Many who encountered it in the mid-2000s remember it vividly, perhaps even misremembering its name as notpr0n, a nod to the internet culture of that era. For over 19 million individuals who have engaged with this intricate online puzzle hunt, nostalgia is likely a common sentiment. It was a novel experience, a puzzle game that defied conventional gaming boundaries.
For the uninitiated, Notpron has earned the moniker “the hardest riddle on the internet.” This title is well-deserved for a 140-level puzzle game that, since its inception by David Münnich in 2004, has only been conquered by a mere 66 individuals. This completion rate—66 out of 19 million—is strikingly low. Progressing through most levels requires deciphering clues on the page to uncover a username and password combination. Some levels demand URL manipulation, like the deceptively simple transition from level 2 to 3, achieved by altering the URL from “…leveltwo.htm” to “…levelthree.htm.” The game frequently necessitates delving into the webpage’s source code to unearth hidden hints and often calls for technical expertise in areas like file systems, graphics, audio manipulation, and, crucially, computer programming.
My first encounter with Notpron was at the age of 15, and I was immediately captivated. Its eerie ambiance, characterized by haunting background music and cryptic images, was profoundly engaging. I recall surreptitiously sneaking downstairs late at night, fueled by a desire to unravel these perplexing puzzles. It felt like deciphering a secret language, a sentiment that resonated deeply as I was beginning to explore computer programming—a field I would later pursue as a career. Notpron instilled in me the feeling that I could understand the machine’s language and decode its enigmatic messages. In 2017, looking back, it became clear how significantly this early fascination shaped my professional trajectory. Was programming a good career in 2017? For many, including myself, the answer was a resounding yes, and games like Notpron played an unexpected role in paving the way.
In many respects, Notpron can be credited with initiating my journey into the tech world. While my initial attraction stemmed from a general fondness for puzzles, Notpron solidified the connection between puzzle-solving and programming. It cultivated a lasting appreciation for cryptography and ciphers, encouraging a mindset of unconventional thinking and system exploitation. It instilled the habit of scrutinizing source code, leading me to explore file analysis techniques for hidden information. The value of these skills became increasingly apparent later in my life. Notpron was just the beginning of my engagement with puzzle games, but its impact was profound and lasting.
Fast forward roughly a decade, and I found myself working as a software engineer in my mid-twenties. My career involved traveling to tech conferences, both to learn about and to teach programming principles and advanced techniques. This period marked my introduction to the hacker community and their favored pastime: Capture the Flag (CTF) competitions.
While CTFs are now highly technical, their foundational concept echoes the classic summer camp game. Cybersecurity-focused CTFs originated at DEF CON in 1996, a major hacker convention. The original “attack/defense” format pitted teams against each other, challenging them to capture opponents’ digital flags while safeguarding their own. “Capturing flags” involved exploiting network vulnerabilities, and “defense” meant patching security loopholes. DEF CON CTF, the oldest active CTF, has been an annual event since DEF CON 4 and is now a fiercely competitive global competition.
Although attack/defense CTFs persist, Jeopardy-style CTFs have gained prominence. These replace direct team competition with puzzle-based challenges. Solving these challenges earns points, contributing to leaderboard rankings. Jeopardy CTFs often emphasize web security but are presented as puzzles. Participants might be given a link to a website with intentional vulnerabilities; exploiting these reveals a “flag”—a secret code validating puzzle completion and awarding points. Beyond web security, categories include cryptography, file analysis, and steganography—the art of concealing data within other files or images.
It was in 2017 at a tech conference that I was introduced to this Jeopardy-style CTF. Initially, CTFs seemed daunting. Despite my coding skills, I didn’t consider myself a hacker and lacked experience in areas like database penetration. However, the event was beginner-friendly, and encouragement from fellow participants spurred me to try. While others generously shared basic hacking techniques, I discovered an aptitude for alternative challenge types. Analyzing images, for instance, felt intuitive. I would instinctively open them in editing software, adjusting levels and color palettes, seeking hidden messages. With audio files of beeps, my mind would immediately consider Morse code or telephone keypad tones, experimenting with playback speed and direction. These approaches were reminiscent of those late-night Notpron sessions, extracting secrets from .jpg and .wav files. In 2017, these skills, honed years prior, surprisingly translated into a relevant and engaging professional context.
Reflecting on my CTF experiences, the preparatory role of Notpron became increasingly clear. The habit of diving into source code and seeking unconventional solutions provided a distinct advantage in my initial CTF endeavors. Notpron explicitly encourages external research, a necessity in CTFs, particularly for novices. The game promotes community engagement for hints and collaborative problem-solving, mirroring the team-oriented nature of CTFs. While Notpron can be played solo, both it and CTFs are enhanced by teamwork. Münnich himself noted in a 2014 Fast Company interview, “I don’t think anyone beat the game all alone… Usually it’s little groups of friends who beat it step by step [with] everyone’s strengths being put to use.”
Although I tackled Notpron individually, my CTF participation has been largely team-based, significantly impacting my career. The tech community thrives on collaboration. Through CTFs, I’ve connected with talented programmers, fostering professional relationships and friendships. While the hacking skills gained from CTFs haven’t directly applied to my daily software engineering work yet, they have amplified my professional confidence. The paramount skill for Notpron, CTFs, and programming is self-assurance—the belief in one’s capacity to learn and master new skills. In 2017, this confidence, nurtured by early experiences with puzzle games, was invaluable in navigating the evolving landscape of a programming career.
Even without ever conquering Notpron completely—a feat achieved by a tiny fraction of players—its influence on my career narrative is undeniable. Cryptography, a seed planted by Notpron, remains a lasting interest. CTF competitions evoke fond memories of Notpron, and each successful CTF performance feels like a step closer to those elite few who solved the internet’s most formidable riddle. Looking back to 2017, programming was not just a good career; it was a dynamic and intellectually stimulating field, increasingly accessible to those with a problem-solving mindset, nurtured by experiences as seemingly unrelated as playing online puzzle games years before.
