You’ve claimed that privacy is the new fame. Can you explain that?

It’s now so difficult to be private that it will be the new state everyone strives for. But I don’t think we have to convince people of the need for privacy, it’ll just happen naturally… [just as] fashion is always going from skinny jeans to bell-bottoms and back again. The generation below always over-corrects to the one before, and you can already see this happening.

You’ve created a messaging app, Wickr, that allows people to message each other in a completely secure, private way. A lot of people would say they’ve got nothing to hide, so why bother?

We’re just trying to be the number one messenger in the world. I think privacy and security are reasons why our users will stay with us because there is no way that your information can ever be used, viewed or kept. The difference between us and what the big companies are doing is that they are encrypting messages between a device and their servers, whereas we are doing it device to device. So, we don’t know who our users are, who they’re talking to or what they’re saying. We can’t hand that information over: we don’t have it.

People my age might feel it’s too late. I’ve been using the internet for many years, and I could start using cryptography now, but what’s the point?

It’s a sort of brainwashing, this idea that resistance is impossible because it is too late. Security is not a state, it is a scale. I spent a lot of time in Tahoe and there are a lot of bears up there. The joke is: how do you protect yourself from a bear? You just need to run faster than your friend. I think that is the case with security, too.

What made you start taking privacy so seriously?

I’ve been lucky enough to be educated by the very best hackers in the world. I have always been a math geek and was coding when I was young, so I understand how the network works. Hackers have shown me what can be done, like what is actually going on in the background and how easy it is to get this information. That’s why I’m trying to teach that to the kids now.

You run a hacking camp for kids and you’ve said you can teach a child how to hack into someone’s webcam in half an hour. Is that really such a good idea?

It’s really important that people understand this is not NSA-level stuff. Those cameras on your laptop, when I see them looking at me, I see an eyeball. It’s actually a hack that happens quite often – also on journalists. The internet has made it so that the kind of things that only high-profile celebrities needed to worry about a decade ago are now what every person needs to worry about because we’re all celebrities.

You don’t reveal where you were born or where you live, and wear dark glasses when you are likely to be photographed in public: what’s the risk involved in that?

I’m lucky that, to date, there are no pictures of my eyes on the internet so that’s just one of the ways I’ve chosen to decrease my digital footprint. The fewer pictures you have of yourself online, the better. A researcher at Carnegie Mellon University showed that he was able to take pictures from high-security cameras, match them with pictures on Facebook and steal your financial identity.

Why are you so hardline about Facebook?

If you read Facebook’s privacy policies, or those of WhatsApp, Snapchat, Instagram, Skype or Twitter, with all of them you’re granting control and ownership of whatever you post on that site to the service. We’re now seeing people’s Twitter photos being put on billboards without them getting paid. I think those people don’t need to, or don’t want to, lose this control of ownership of their baby pictures but they don’t realise it’s happening.

You describe yourself as “properly paranoid”. Is that what we should all be?

If people really understood what was going on, they would be. To me, the NSA and Snowden are just the tip of the iceberg. I don’t have personal conversations that I wouldn’t want to read in a newspaper on email and SMS, nor a phone call unless it’s encrypted with Wickr. I assume all those are public conversations. I’m very careful with Google searches. I wouldn’t do any healthcare search without using a VPN [virtual private network] and a small search engine such as Blekko. And if I’m buying booze for a party I’ll put it on cash instead of a credit card. I think the health insurance companies are very much looking at everything you do and buy. It’s all being watched.

It’s not just about privacy, but about changing the entire business model of Silicon Valley. Isn’t that a tall order?

The big difference is that we are giving away all control to the user. We have no idea who our users are or what they’re doing. Imagine telling investors that. It’s a new world and we have to find a new business model to make money in a different way.

How do you find the male-dominated culture of Silicon Valley?

I think the walls are gone; more than 50% of hackers are girls. I took my 14-year-old daughter to a breakfast of women investors and she listened to them talking about how tough it was to be one of the first female investors in Silicon Valley. When we left the breakfast, she said to me: “You know what, Mom? Those problems don’t exist anymore. It’s obvious that girls are smarter at math and science.”