a longer version of this blog post is available on the MIT Media Lab’s Digital Currency Initiative platform With Google Trends data showing that searches for the word “blockchain” have exponentially increased, we may be entering the peak of the hype cycle for blockchain and distributed ledger technology. But here’s the thing: the blockchain is a major breakthrough. That’s because its decentralized approach to verifying changes in important information addresses the centuries-old problem of trust, a social resource that is all too often in short supply, especially amid the current era’s rampant concerns over the security of valuable data. It turns out that fixing that can be a boon for financial inclusion and other basic services delivery, helping to achieve the global objectives laid out in the Sustainable Development Goals (SDGs). Sorting out hype from reality may depend on how well we identify where institutions that have until now played a role in mediating trust between people are falling short, especially in the key area of money. Deploying the blockchain in those settings to generate secure, decentralized trust could achieve great strides in inclusion and innovation. What do we mean by decentralized trust? The concept is unfamiliar in part because its converse — centralized trust – is something that we often take for granted, at least while it’s working. But if we look at the history of transactions since the early barter systems to modern-day digital money exchanges, we can see how different trust protocols for keeping track of our exchanges of value have evolved and how, in each case, centralizing trust within particular institutions has periodically caused problems. As strategies for dealing with this challenge evolved and as the complexity and frequency of transactions grew, different trust bearers emerged. We went from relying on the memory and discretion of tribal leaders, to central governments issuing currencies in the form of precious metals, to commercial banks acting as trusted intermediaries and issuing their own bank notes, to central banks managing a hybrid system in which sovereign fiat banknotes circulate alongside a debt/credit form of money managed by regulated banks and internal ledgers.