For a company like Google, big data means big business. The growth of the tech giant has been enabled by its ability to harvest vast volumes of personal data from user’s online searches, browsing habits, and email inboxes. What it does with that data has become a source of increasing concern over recent years.

This concern started with the 2013 Snowden revelation that the NSA was accessing individual Google accounts to spy on people. Since then, there has been a shift in the public’s awareness of Google's usage of our data. We now know definitively that not only are we Google’s consumers,we are also their main product. Our data is their product, packaged and sold for profit for unclear purposes to interested bauyers.

Recently, Google’s sibling Sidewalk Labs has given cause for further privacy concerns to citizens in Toronto. The company, which is owned by Google’s parent Alphabet, is partnering with government organization Waterfront Toronto to revitalize a 12-acre area of land next to the lake. The Sidewalk Toronto website offers up plenty of grand words: “world-class archetype of post-industrial innovative urban development” being a prime example.

However, concrete details of what is planned are somewhat lacking. What is apparent is that data and connectivity will be significant features in play. In light of Google’s track record of using personal data for its own gains, it is understandable that Sidewalk Toronto’s critics in Canada are now becoming more vocal. People are starting to consider what the development will mean for the privacy its residents. Moreover, who is going to profit from the data collected?

One Waterfront Toronto developer has reportedly resigned in protest over the lack of willingness from project participants to discuss details pertaining to data privacy. A year on from the announcement of the partnership, it is still not clear who will own the individual data generated from the Sidewalk Toronto project. A smart metropolis may offer advantages in energy efficiency and waste management. But it could also quickly become an Orwellian nightmare if a private company is running the show for the purposes of data collection.

Of course, Google is not the only company profiting from invasions of privacy. As things stand though, increasing interconnectedness and dependence on technology means we currently have little choice other than to surrender our privacy.

However, developments in blockchain indicate that this could soon change.

Self-Sovereign Identity and Consent

A key component of blockchain is its use of public key cryptography. Each individual has their own public key and private key. Because the private key is known only to its owner, it can serve as a digital signature of approval for a transaction to take place.

Providing a private key could also apply as consent for the processing of an individual’s personal data for any purposes, including third-party tracking cookies for serving targeted ads. This is the principle used by Basic Attention Token (BAT).

Users will download the BAT browser, called Brave. Once they start surfing the web using Brave, they are safe in the knowledge that their data is protected from harvesting by third-party tracking cookies. They are also eligible to receive the BAT digital tokens as a reward for their time spent viewing advertisements.

Smart Contracts

There is data that should remain private and confidential which is not necessarily personal in nature. Financial transactions are one example showing why permissioned distributed ledgers have been a more prudent choice for financial institutions interested in blockchain.

Now, a new development called “secret smart contracts” could enable the private storage of data on a public blockchain. Blockchains such as Ethereum allow the automatic execution of smart contracts, with the results stored as a permanent record. However, on a public blockchain, this data is then not private.

Enigma is developing a new protocol that will run on top of existing blockchains such as Ethereum. It uses a technology called Secure Multi-Party Computation to ensure that the contents of smart contracts remain completely confidential. The technology breaks a contract code into multiple sections, which are then encrypted independently from one another. By doing so, the contracts are unintelligible to any single party on the network.

Public Blockchain, Private Data

ReBloc is developing a solution for the real estate big data marketplace using smart contracts to assure data confidentiality on their platform. Real estate data is notoriously fraught with issues around its integrity and quality mainly due to the small number of providers dominating the market. By using blockchain to create a secure data marketplace, ReBloc hopes to level the playing field and open up opportunities for smaller players to enjoy the benefits of big data that is both accurate and accessible.

Rebloc is also developing a protocol to validate the integrity of the data being sold in the marketplace. When a user is interested in purchasing data from a vendor, a smart contract opens containing a validation layer which compares the data offered against other datasets to determine its accuracy. Once it has validated the data and without any third party intervention, it releases it to the user and sends payment to the vendor. In this way, the system is trustless and users can rely on receiving accurate data.

Zero-Knowledge Proofs

Zero-knowledge proofs offer a way for the nodes of a blockchain network to verify the truth of a transaction, without knowing the contents of the transaction itself. Chronicled is a blockchain project employing this to great effect in managing supply chains.

In a supply chain, a procuring party doesn’t want the pricing or supply volume for each supplier to become public information. Therefore, Chronicled uses zero-knowledge proofs to keep the transactions within the supply chain confidential. A supply chain transaction is verifiable, without requiring users to disclose all the details behind it.

As things stand, blockchain adoption is in the very early stages. However, in the face of companies like Google keeping a stranglehold on our right to data privacy, blockchain solutions offer a glimmer of hope for concerned individuals. Perhaps in the future, blockchain will be the technology of choice for ensuring sovereignty over our personal data.