Challenging puzzles on the internet disguised as recruitment tools

Trying to solve online puzzles or brain teasers may sound fun, but when the difficulty levels up tremendously with some challenging puzzles, you may need a specific set of skills. We’re talking cryptography, programming, and math.

In the online world, here are 5 particularly famous online puzzles which are used by some governments to suss out the cream of the crop, and reward the victors with a career opportunity.

Cicada 3301

If you’re into internet puzzles, you might’ve heard of the Cicada project. Probably the most enigmatic mystery on the internet, Cicada 3301 promises an “epiphany” for “highly intelligent individuals” who can solve it. Only a handful of the world’s brightest minds have cracked it since it began in 2012 on 4chan’s /b/ and /x/ boards (there were follow-up puzzles in 2013 and 2014, which no-one was able to solve).

The puzzles involve cryptography and steganography, peppered with super obscure clues ranging from Anglo-Saxon runes to occult philosophy. The puzzles begin with an encrypted message, with clues that lead to real-life locations around the world. Like a spy game, players followed images of a cicada pasted on telephone poles that contained the next clue.

No one knows who 3301 are, or what their purpose is, and some speculate that the puzzles are recruitment tools for a government agency, such as the NSA, CIA, or MI6.


Project Architeuthis

Project Architeuthis is the US Navy’s recruitment campaign, disguised as an alternate reality game (ARG), to attract experienced cryptologists back in 2014. The game starts with the kidnapping of a Navy engineer, and a series of clues are served up via social media as to his whereabouts (a secret lair).

Players have 18 days to rescue him, with help from a cryptologist who sends a series of encrypted messages each day. The clues get increasingly obscure – the end goal is to find the location of the sub and catch the bad guy. Along the way, players can help each other with various brain teasers and interact with a number of fictitious characters through their fake social media footprints.

Project Architeuthis comes from the Navy’s ad agency Lowe Campbell Ewald, and the quest ends when the first 10 people submit the right answers to the Navy via an email address that comes with the final puzzle.


Codebreaker Challenge

The US National Security Agency (NSA) has their annual Codebreaker Challenge designed  mainly to recruit American students interested in cybersecurity. In the game, participants assume the role of an NSA employee who takes up a challenge based on current, real-life scenarios.

Each year’s challenge has a different theme, and comes with its own (fictitious) backstory. This year’s challenge focuses on network protocol analysis, binary reverse-engineering, and blockchain. For the challenge, participants are tasked with overcoming a ransomware that involves an encrypted key linked to the Ethereum blockchain for ransom payment. They not only have to unlock the ransomware without giving in to the attacker’s demands, and recover all the funds paid by other victims.

Since this is an official recruitment tool, students need to register for the game with a US university email address.


Can You Crack It

The UK’s GCHQ (Government Communications Headquarters), an intelligence and security organization, also has an online code-breaking game recruitment tool: Can You Crack It. The three-stage quest involves a number of visual puzzles, math problems, cryptography, JavaScript programming and reverse engineering, among others.

Some of the questions had multiple layers of answers, while others were hidden clues. Unlike Cicada, the questions were in one website, and the solutions were less time-consuming, as it focused on cybersecurity skills relevant to the intelligence agency. GCHQ also released a five-part Christmas puzzle in 2015 where solving one part unlocks the next.

The agency has also launched a print version of its puzzles, so you can test your skills the old-fashioned way.



Created in the UK in 2015, CyPhinx is a virtual skyscraper where players access cybersecurity challenges and interact with fellow cybersecurity enthusiasts. Basically a 3D immersive platform where they can demonstrate their skills to fellow players and potential employers, it’s part of CSA Singapore’s recruitment tool in the Cybersecurity Challenge Singapore.

The Singapore floor has four games: ‘The Enemy Within’, ‘Cyber-Tent’, ‘Whitehatters Webapp’ and ‘Pen-Ding’. The aim is to get as many points as possible upon completing challenges in cybersecurity disciplines such as forensics, vulnerability assessment and network security. The top 6 players will pit their skills against UK players in the Masterclass final and win career-enabling prizes.

As this serves as a recruitment tool for the CSA, it’s only open to Singaporeans and Permanent Residents, as long as they’re not in the cybersecurity field.