Big data and artificial intelligence, pitched as freeing us from human frailties, are becoming powerful tools for social control. This is occurring along two parallel tracks: surveillance authoritarianism and surveillance capitalism. Through massive data collection and aggregation, China’s social credit system envisions an airtight regime of perfect compliance with legal and social obligations. Many other governments, including liberal democracies, are adopting similar techniques. The potential for catching terrorists, child predators and tax evaders is simply too appealing – whether it’s the real objective or a cover story. Meanwhile, private digital platforms are using troves of data to shape online experiences consistent with their business models. What you see online is, increasingly, what maximises their profits. Companies such as Google, Amazon, Tencent and Alibaba can build the best algorithms because they have the most data. And they aren’t interested in sharing.

Regulatory interventions will fail to derail the self-reinforcing momentum for ever more centralised data repositories. They may even accelerate it by creating layers of compliance obligations that only the largest firms can meet. Europe’s General Data Protection Regulation, for example, actually increased the market share of Google and Facebook in online advertising, and so it is not surprising to see such incumbents actively welcoming the prospect of more regulation.

The only lasting solution is to change the economics of data, not to impose private property rights; that would accelerate the market forces promoting data centralisation. Giving you ‘ownership’ over your data means giving you legal cover to sell it, by clicking 'OK' to a one-sided contract you’ll never read. The problem is not ownership, but control. In today’s algorithm-driven world, sharing and aggregating data increases its value, producing better models and better predictions. The trouble is that once we share, we lose control to centralised data hogs.

What we need is a technology that allows for sharing without giving up control.

Fortunately, it exists. It is called blockchain. Blockchain technology is, fundamentally, a revolution in trust. In the past, trust required ceding control to counterparties, government authorities or intermediaries who occupied the essential validating roles in transaction networks. Blockchain allows participants to trust the results they see without necessarily trusting any actor to verify them. That’s why major global firms in health care, finance, transportation, international trade and other fields are actively developing cross-organisational platforms based on blockchain and related technologies. No database can provide a trusted view of information across an entire transactional network without empowering a central intermediary. Blockchain can.