Want to be a spy? If you can solve these puzzles, the Government Communications Security Bureau wants to hear from you.
"How good are you really?", reads the challenge from the intelligence agency. "Crack this code and prove to us you have what it takes to work in intelligence."
There are three "code cracker" tasks from the GCSB, which has left its shadowy past behind to openly seek out recruits as it boosts its numbers.
Each of the codes is a string of apparently unintelligible letters or numbers.
Apparently unintelligible - but not for some.
For, says University of Auckland mathematics professor Arkadii Slinko, there are others "fascinated by the internal beauty of these codes".
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They are, he says, an "invitation" to those who see "beauty" to dive into the world of intelligence gathering.
The GCSB is New Zealand's "signals intelligence" spy agency - our nation's "electronic eavesdropping" contribution to the Five Eyes network which also consists of Australia, Canada, the United Kingdom and the United States.
Other partner agencies have used similar recruiting exploits. In the United Kingdom, the Government Communications Headquarters launched its first puzzle challenge in 2011, saying: "Decoding plays a direct role in predicting and thwarting major attacks."
The GCHQ puzzles became so popular the agency published a book which went on to sell 300,000 copies.
The most famous of modern cryptography solutions also began with a puzzle. The Bletchley Park team who formed around Alan Turing to break the German's Enigma code in World War II was formed, in part, through
• Scroll to the bottom for answers
Slinko, whose lectures include the history of cryptography, said there are those who have a natural inclination to maths, which creates an affinity to code cracking.
He once asked a student if she read on long plane journeys. "She said a good mathematical problem is better than a volume of Shakespeare's works.
"People are very different. Some enjoy solving puzzles and some don't. Some enjoy painting pictures. Some brains are wired in a certain way."
He said while encryption has enormous application and value across the private sector, there is the occasional note in his pigeonhole asking he alert students to possible careers with the GCSB.
The new GCSB recruiting campaign is anything but furtive.
Like its offshore counterparts, the bureau and its sibling agency, the NZ Security Intelligence Service, were forced out into the light after whistleblower Edward Snowden's disclosures in 2012 demanded greater accountability and openness.
Those demands were even greater in New Zealand after the GCSB was caught that year having illegally spied on entrepreneur Kim Dotcom.
A report published in 2013 revealed the bureau had become estranged from its legal baseline and healthy public sector good practice.
The GCSB, which also has responsibility for New Zealand's cyber protection, has undergone a massive overhaul since.
In that time, both the GCSB and NZSIS have received huge funding boosts - and gone a huge recruiting drive. Part of that recruitment exercise has been to improve diversity at a place previously seen as very male and mostly Pakeha.
GCSB director-general Andrew Hampton said: "To put it simply, our mission is to protect New Zealand and New Zealanders."
He said the bureau needed a diverse workforce which was strong in science, technology, engineering and maths.
The drive towards diversity reflected the positions taken by Five Eyes' partners - a former GCHQ director said "dull uniformity would completely destroy us".
Hampton said reflection on the GCSB workforce in 2016 found "room for improvement".
It had since reduced a gender pay gap of greater than 10 per cent - skewed against women - to 5 per cent. The bureau also now offered scholarships to women wanting to study in areas it considered critical.
While slightly more than half of senior leaders were now female, its overall staff was only about a third women.
In the technical trades of science, technology, engineering and maths, just 16.5 per cent of staff were female.
"This lack of females in technical roles is unacceptable and a barrier to us fully addressing our gender pay gap," Hampton said.
While statistics showed men traditionally dominated the numbers of those working in those fields, he said there were a number of innovations to redress the balance.
The scholarship programme had also raised the profile of the GCSB as a potential employer among women. Of 300 recent applications from graduates, 124 were from women. There were eight jobs going - women got five. Just two years ago, only 14 per cent of applications were from women and none were hired.
Last week, the States Services Commission issued its latest "health check" on the intelligence agencies through its Performance Improvement Framework system. The reports benchmark government agencies and challenge improvement.
The latest report is glowing - a contrast to those issued in the wake of the Dotcom debacle.
Reviewers described the change at the GCSB and NZSIS - which had similar issues - as "an impressive catalogue of organisational transformation".
They found the changes required saw "the need for fundamentally re-thinking" almost every aspect of the organisations operation".
"The agencies can be confident they are on the right track."