 So, I can fix fraud on online marketplaces. After finishing my bachelor's degree, I had a bunch of textbooks that I wanted to sell. I managed to sell most of the textbooks to local students with no problems. But one of the books in particular I found very hard to sell. I made a few offers online, but all of them lived too far away to meet up physically to do the exchange. I was hesitant to send the item before receiving the payment, fearing that I might get scammed and vice versa. And in many ways, my fear was justified. Over half of all IT-related crime in Denmark concerns fraud on online marketplaces. Every six minutes, a dame gets scammed on an online marketplace. Almost 100,000 cases each year in Denmark alone. In the end, I never did sell my book, which to this date collects dust on my bookshelf. So, for the past four years, I have researched how to facilitate online trading in a provably secure way using a technology known as blockchains. I have proposed a system that is functionally similar to eBay or Amazon from the user's perspective, but offers three distinct advantages. One, it's provably not profitable to cheat. Two, it decentralizes common infrastructure and offers some resistance to monopolization. And three, it supports full cryptographic protection of the user's privacy while also ensuring compliance with laws and regulations. So the system works roughly as it follows. So we have the buyer and the seller that interact over the internet, and they have a contract at their disposal that automatically processes payments for them. So what the buyer does is that they deposit the payment into the contract, and then the payment is forwarded to the seller once the buyer confirms delivery of the item. To deal with fraudulent behavior, the buyer can issue a dispute by putting more money into the contract. In this case, the seller is given the option to either forfeit, in which case all the money goes back to the buyer, or they can counter the dispute by also placing money into the contract. In this case, what we do is we solicit a decentralized set of jurors who live in other countries, potentially, and we ask them, who was the honest party here? And that party is then returned the money that they were supposed to have, while the leftover money is used to pay those jurors that made the majority decision. And this system forces the buyer and the seller to only make disputes if they are convinced that they were the honest party. So through a careful mathematical analysis of the incentives, I have shown that in this system, crime doesn't pay. Perhaps in the future, I might be able to sell my book. Thank you.