A Kiwi tech start-up is working on a radical way to protect data privacy in New Zealand.

You've probably never heard of the company - Centrality - but it's been meeting with both the Government and banks.

It's working with Blockchain, a technology that is attracting a lot of interest from investors - and on the global cryptocurrency market Centrality is valued at $388 million.

So how did it get there?

Centrality's value has gone from zero last year and initially privately raised $21 million. It then went public and raised another 111-million - taking it to $132 million and is now today valued at $388 million.

Based in central Auckland, Centrality has 70 staff and is growing all the time. Chief executive Aaron McDonald says its value is growing too.

"You could say we are worth $690 million, roughly."

Which is why the companies Japanese investors were in the country on Monday, checking it out - its blockchain engineers creating blockchain technology that could cause major disruptions to the way we do things.

"We're doing a lot of cool things, new things - kind of inventing this wave of technology and the way the internet could work in the future," Mr McDonald says.

Centrality is what's called a Blockchain studio, creating products that use the technology. So what is blockchain?

If you take a money transfer at the moment, that goes via a bank, a safe middle-man, to protect the transaction.

But under blockchain, there's no need for that middle man because it's unhackable - essentially, it is safe because the transaction is locked in with other people's transactions.

The whole lot is then copied to thousands of computers around the world, creating one massive decentralised database - and the power of the group means no one can tamper with the transaction.

It has been floated publicly by issuing what's called tokens instead of shares, and people are investing in it using a cryptocurrency called Ethereum.

The major crypto-market Coinmarketcap says the Centrality token ranks at Number 66 in the world, and is worth about US$0.42 (NZ$0.58).

There are 679 million Centrality tokens in supply, which is a equivalent to market value today of US$283 million (NZ$393 million).

And in the last 24 hours, $520,000-worth of the tokens have been traded. The total supply is 1.2 billion tokens, meaning another 500 million are yet to be released.

But globally respected technology commentator Richard MacManus says people shouldn't believe the hype.

"The problem with blockchain companies at the moment is that we are in a bubble - so people are speculating wildly on these cryptocurrencies and blockchain companies in the top. They appreciate rapidly."

In full effect, Blockchain would mean that Facebook would no longer own the data like it let Cambridge Analytica abuse. Privacy, freedom and control would be returned.

And Centrality says work is underway with banks and the Government on what it calls "an identity project", where New Zealanders would have an unhackable identity.

"The idea behind that you don't have to trust a central agency or a tech company with that identity information it's yours, it's locked with your key on the blockchain," Mr McDonald says.

The Department of Internal Affairs controls the way Kiwis are identified and has confirmed discussions with Centrality have taken place over the use of blockchain.

The question is: will it live up to the hype?

Newshub.