Here's everything you need to know about blockchains, the ground-breaking tech that could be as disruptive as the internet

From a 'castle' full of bitcoin millionaires to the initial coin offering (ICO) craze, it's hard to escape the chatter about how some people are building their fortunes off the new world of cryptocurrencies. But behind those cryptocurrencies sits a technology called blockchains, which some people believe could fundamentally rewrite how transactions are handled online.
With analysts at UBS estimating that blockchains could be a $300 billion to $400 bi