大象传媒

As bitcoin's bubble is bursting, with the crypto currency trading at less than a third of its peak price, investors are looking at its underlying technology: blockchain. But what is it? David Shrier of Oxford's Said Business School tells us what it is and how it works, and Jamie Smith, chief executive of the Global blockchain business council tells us what you use it for, including land title records and tracking meat. One of the key problems for the billion or more poor people around the world is being denied access to any form of conventional banking. Joseph Lubin has founded a company called Consensys which uses blockchain in a way that he believes will address this problem. And we hear from David Prager of DeBeers, which is using blockchain to track diamonds. Ed Butler presents. (Picture: David Prager, DeBeers executive VP of corporate affairs, holds a rough diamond in the company's offices in London. Credit: 大象传媒)