A growing chorus of technologists want to flip the Web on its head, to counter the increasing dominance of massive platforms like Facebook and Google. They say the technology underpinning digital currencies like Bitcoin makes it possible to transform the way we store and share data online—from today’s highly centralized model, where a few companies hold all the cards, to something more reminiscent of the Web in its earlier days.

But this vision will hinge on much more than technical innovation; it also faces complicated economic and social barriers. That’s a big takeaway from a new analysis (PDF), published by MIT researchers, that takes an in-depth look at problems associated with centralization—censorship, algorithmic bias, and privacy and security concerns, to name a few—and at potential avenues for breaking things open.

A promising technical approach is inspired by the digital currency Bitcoin, which has made it feasible for people to make digital payments peer to peer, without a central bank or credit card company as an intermediary. Bitcoin’s power lies in its blockchain, a cryptographic ledger that records every single transaction and is accessible to anyone with the Bitcoin software. Maintenance of the Bitcoin network is carried out by computers all over the world, so no central authority is in charge (see “What Bitcoin Is, and Why It Matters”).

Blockchains can be used for other things besides payments, too. The company Blockstack, for example, uses a blockchain to track usernames and encryption keys, the basis of a new kind of identity system that would not be tied any single social network or other website.

It’s a promising approach for giving individuals more control over their data. But breaking old habits and challenging entrenched business models is very difficult. Besides Blockstack, the MIT researchers examined several other early examples of decentralized services, finding a common thread: “The challenge is not just building decentralized software and creating alternative platforms, but creating options for users that are financially sustainable, usable, and compelling.”