When questioned about what his job entails, Roger Sutton pauses for a minute, slowly deliberating about what he's permitted to reveal.
"Let's just say at certain times there have been elements of danger in my job," he responds, carefully.
His furtiveness is understandable. The 64-year-old Brit has made his livelihood from keeping classified information under wraps and, for the past 24 years, he has worked for Crypto AG, a Swiss firm specialising in communications security.
When industries, governments, secret services and militaries want to transmit sensitive information in strict privacy, Sutton's the man they turn to. His firm makes sure emails, faxes, phone calls and radio signals are completely secure.
Nevertheless, when pressed, Sutton, who's been based in Crypto's Abu Dhabi office for the past decade, is prepared to impart certain anecdotes from his career, albeit in scant detail.
"One of my scariest moments was in Kuwait City in 1990 when Iraq invaded, but I managed to get out just at the last minute. This was fortunate, as let's just say the reason I was there was not unrelated to the invasion," he recalls.
"And I've been dropped by helicopter in the jungle right in the middle of a combat zone, where we were fired at by rebel armies."
However, Sutton is at pains to point out he's not some kind of heroic super-spy.
"No, I'm not a secret agent by any means. I'm an engineer by training, so I'd say I was more of a Q-type figure than James Bond. It's more technical stuff than actual espionage work," he admits.
"But I've been doing this so long I've got lots of lovely stories that I could divulge, but obviously I can't. My best advice would be to read my book, as this, and a sequel I've planned, will be the closest you'd get to hearing some of my career stories.
"There's plenty [of truth] in there. Obviously I can't specify what and, of course, because it's fiction, I have embellished some of it."
The book is A Need to Know, Sutton's debut, self-published novel. With a plot involving a succession of brutal murders, a terrorist assault on a US aircraft carrier and, perhaps most implausibly, a helicopter smashing into the Burj Al Arab, he's clearly not averse to enriching his yarn with some far-fetched storytelling.
Witness to all the this carnage is our hero, Mike Ashley, a journalist for Jane's Defence Weekly, the famous military magazine, whose "tough childhood environment amongst the steel mills of South Yorkshire had instilled a healthy dose of resourcefulness and tenacity".
Haunted by the death of his beautiful Indonesian bride in a terrorist attack, he's commissioned by the British secret service to track down a leading cryptologist who vanished just before he's meant to deliver a keynote speech at a military conference in Toronto.
Ashley jets off to the Canadian city to find the missing expert but, in a familiar-sounding plot device, he cracks a secret code hidden in a crossword clue that portends a terrorist attack in the Gulf. Hence, the action swiftly moves to Dubai's luxurious hotels, lush golf courses and seedy nightspots.
However, those with a knowledge of football's English Premier League might question why Sutton's named his central character after Newcastle United's controversy-courting, billionaire chairman.
Sutton says: "When I wrote this book in 2006, Newcastle's Mike Ashley wasn't so well known, and so I thought nothing of naming him Mike. In fact, I wanted to call him Rick, but my daughter said he might be confused with the singer Rick Astley. That was a shame, because I liked the name Rick, it kind of created a face in my mind."
Sutton is keen to distance himself from suggestions that Mike might actually be Roger, despite the fact that both he and his protagonist count Sheffield as their hometown.
"We're both from the same city, yes, but that's where the similarities end," he explains.
"I think Sheffield is a kind of unfortunate place. Its industrial base has collapsed, and its football teams are both underachievers. Making Mike a Sheffielder automatically makes him an underdog.
"He's from a tough place and he's a tough guy. But as this is my first novel, I've put a bit of myself into him, as I have with all my characters."
Another of the book's protagonists is Samir, a Jordanian encryption expert whose disdain for Dubai's drive towards modernism leads him to affiliate himself with religious fundamentalists. Although Samir abhors violence, he's determined to make sure "the insane rush to turn Dubai into an Arab Disneyland would come to an end."
Sutton hints that Samir's predicament is mirrored in reality.
"Basically, he's just an intelligence engineer, who's thrust into this position and ends up with access to more information than he should have. It's quite true to life that people in this position are under pressure from various agencies to go into espionage work or sell their secrets. As Samir, because of his beliefs, finds himself coerced by terrorist organisations, without fully realising the consequences of his actions."
But Sutton is keen to point out that, despite being privy to classified information, choosing Dubai as a target for a possible terrorist atrocity is based on familiarity with the city, rather than any inside knowledge.
"I'm not aiming to alienate or upset anybody, after all it is a fictitious story, but Dubai is a place where all these cultures meet.
"For the book, I needed a place that arguably could be seen as a terrorist target. It could have been anywhere, but Dubai does have a large western population, plus having lived in the country for so long, I know Dubai very well."
The exotic locations, the rip-roaring set pieces, combined with Sutton's authoritative knowledge of the world of espionage, seems to have all the ingredients for a successful spy thriller. Unfortunately, thus far, the major publishing houses have spurned his advances.
"It's a complete nightmare," he says as he recounts the succession of rejections A Need To Know has received. "It can be very frustrating and very depressing."
Nevertheless, he's dug deep into his own pockets to have Matador, a UK-based self-publishing firm, release the book and his e-book can now be downloaded from Amazon, while a few bookshops in the UAE have also agreed to stock hard copies.
Sutton advocates this self-funding route, albeit with a few reservations.
"If your goal is to see your book on a bookshelf, then you should do it. If you're expecting to come away with a pocket full of cash, you'll be disappointed. There's a lot of investment to cover before you get anything back. Like every writer, you hope your book will end up on somebody's desk, who'll then want to take it on as a movie or a TV series. At least if it's out there, you still have this hope.
"But whatever happens with my book, I've had a very interesting career and I hope I've given some insight into that with my writing."
Naturally, it's entirely up to the reader to ascertain what is based in fact and what comes from Sutton's outlandish flight of fiction.