Surveillance footage can be transferred using only modest amounts of bandwidth.
The business is based on four interwoven revenue streams - video surveillance as a service subscription via the cloud, mobile data services, platform licensing fees and hardware sales.
But the Watties soon realised having a product on the market and their business processes and structures in place weren't enough if they wanted to develop the business quickly. They approached angel investor and entrepreneur Scott Gilmour for advice on raising capital to fuel their expansion plans.
They'd first met Gilmour through the Software Association. Initially, it was not their intention for him to invest in the business - they simply wanted his advice on where to look for investment, says Helen.
"Scott quickly introduced us to the possibility of gaining angel investment at a critical growth stage of our business."
Gilmour, meanwhile, was an established angel investor, having worked at Intel for more than 12 years and was founder of the "I have a Dream" charitable trust in ths country.
Mi5 security was an interesting-sounding investment opportunity, he says, but he was initially more attracted by the founders' commitment to the company.
"I got to know them and the company and I just thought they were good people, which is my prime requirement for getting involved."
Gilmour is a founding member of the Ice Angels, the largest group of angel investors with more than 100 members. With a decade of Ice Angels experience, as well as seven years on the advisory board of Trade and Enterprise's Beachheads Initiative (which connects companies to a network of private sector advisers), Gilmour says between 30 and 40 companies present their business plans to him every year, but few grab his attention like Mi5 did.
Gilmour became chairman of Mi5 Security in July last year and has since raised more than $1 million in two finance rounds, helping pave the way for the company's expansion into Britain.
From their earliest discussions Gilmour understood Mi5's proposition, Helen says, and having such a good and committed chairman has been instrumental in helping the company to grow quickly.
"Without Scott as the communication gateway between ourselves and our investors, we'd find ourselves crippled by paperwork and frustrated by the time spent educating people on our business and justifying our decisions."
Like many high-tech start-ups Mi5 isn't profitable yet as it's reinvesting for growth, but it already has many customers here and in Australia and channel partners, as well as a growing UK and mainland European presence.
But it faces the same challenges all Kiwi tech companies do, says Gilmour: access to capital, management capabilities and distance from market. So the Watties are now based in London.
Produced in conjunction with the Angel Association of New Zealand.