"And we have to do that by covert means because when people are planning to do ill to the country, they will try to keep that secret ...
"But the purpose of it is security. The purpose of it is not to spy."
Kitteridge says part of her pitch last year to get the job was to make the service more open and to explain itself better to win public trust.
What is obvious is that she is on a public relations drive to change the public's image of SIS agents from bumbling raincoat-wearing sneaks to ethical young patriots who want to protect New Zealand and always within the constraints of the law.
It is also clear it is not going to be unhelpful for Prime Minister John Key to have Kitteridge also talking about the new era of "crowd-sourced terrorism" by Islamic State (Isis) ahead of his own security speech next week on foreign fighters.
She is giving her first interview in a room off the austere-chic foyer of the SIS building in Wellington which is shared with the GCSB, the intelligence section of the Department of Prime Minister and Cabinet, and a few other acronyms peppered through the NZ intelligence community.
Theirs is a strange existence. Once they get to work, they must surrender their smartphones to a locked drawer in the cellphone locker room and cease texting, Twitter and Facebook use.
They make their way to the lifts through a turnstile that looks ordinary but which is designed to trap any would-be tailgaters with panels that snap almost together if more than one person is detected.
It's designed to bruise and hold rather than sever or kill but you wouldn't want to test it.
Kitteridge shows off her office and the view she would have over playing fields and Thorndon villas if it weren't for the fact she has to keep her blinds pulled all day with Kevlar-like material that must feel as if she is perpetually working in a Waikato fog.
Down the corridor is Ian Fletcher, the head of the GCSB, which she investigated after its illegal spying of New Zealand resident Kim Dotcom shortly before the FBI raided him in January 2012.
Kitteridge watched the Moment of Truth event in the Auckland Town Hall hosted by Dotcom, and featuring NSA leaker Edward Snowden via satellite from Russia, and the journalist who wrote Snowden's story, Glenn Greenwald.
Greenwald himself was of no interest in terms of security.
"He is a journalist. He has freedom of speech. He is entitled to come here and do his thing."
But she was annoyed over the claims of mass surveillance.
"It's ridiculous. It's not happening, full stop. Not even mini-surveillance let alone mass surveillance.
"What I can say is I absolutely did see what was going on at GCSB and there is no mass surveillance of New Zealanders."
She said the image of a typical SIS officer as an older man was rooted in the Cold War days when the focus was on Russian espionage, but the SIS had well and truly moved on.
And the old image was an anachronism to the reality of today's 250 or so SIS staff with whom she meets every fortnight, including those in Auckland via video, in what she calls a town hall meeting.
"I had a town hall meeting today ... What struck me is that it is not older men but young dynamic lively people, parents, people who go to the supermarket, people who go to the creche.
"The thing that they share in common is that they really want to make a difference for New Zealand and the thing I love about it is that they apply themselves without any expectation of recognition and in a way I just think people would find admirable."
So what did they discuss at this week's town hall meeting?
What happened in Canada last week -- a soldier deliberately run down by a car and another soldier shot while standing guard at a memorial in Ottawa -- was one of the main issues.
She said it was a wake-up call because New Zealanders saw Canada as "quite like us" and it was disturbing in that such situations would be very difficult to stop.
This is where she talks about "crowd-sourced terrorism", a new term to describe lone-wolf acts of terrorism conducted by people who show no intent, after exhortation by Isis on the internet.
"What [Isis] is doing is they are sending out this material which is awful, it's all on the internet ... urges people to do small-scale attacks that are not complicated, that don't require planning, that don't require anything fancy, nothing more than a knife or a car or something you can light a fire with that will cause the maximum fear and devastation and havoc and loss of life.
"That is the explicit message and it is to attack the West."
All that that was needed was intent. Capability was not difficult to put together and the whole purpose was to create a sense of terror in the population.
"I think that whole model of crowd-sourced terrorism that is actually very dispersed and where any individual can do it and they are not concerned about their own life is a very disturbing change."
So what is a good day at the office for an SIS officer?
"A good day is when you know that through your efforts and through finding many, many different strands of intelligence and being able to create a picture, you are in fact making a difference to the safety of New Zealanders. And I have seen that." You almost never get a "king hit" in terms of getting information, she said.
"It is not a perfect science. But I have seen a real difference."
Lives saved?
"Yes."
Rise to the top
Rebecca Kitteridge doesn't have a favourite Bond movie but she does have a favourite Bond: "Sean Connery, classic, he's the one and only Bond for me."
She likes John le Carre and the novels of Stella Rimmington, the former head of Britain's MI5. She has also read the essays of Eliza Manningham-Buller, another MI5 director who argued in the Reith lectures that freedom and security aren't mutually exclusive but that you must have security in order to have freedom.
When she was asked recently by a woman "What do you do?", and she replied she was the SIS director, the woman said "Oh, is that an insurance company?".
Kitteridge, who went to Upper Hutt College, wishes she had joined the SIS when she was younger.
"I think it would be a fabulous job and if only I'd thought of it when I was at university."
Instead she graduated from Victoria University and became a lawyer, later joining Crown Law where she was seconded to the Cabinet Office, advising on decision-making processes. The legal division in Foreign Affairs until 2008 was followed by a return to the Cabinet as Secretary, where she was a stickler for process.
She left to conduct the GCSB inquiry, then won the top SIS job. She is aged 48, and married with a 12-year-old daughter.
