IOHK | WHY WE ARE BUILDING CARDANO | 06/28/2017    tokens with real dollars. This fraud cannot be detected by a cryptocurrency unless the dollar itself was a token accounted by a digital ledger . 25 Finally, the representation of entities online is a classical network problem dating back to early days of the internet. Universities, businesses, government departments and any arbitrary users need to establish their identity at some point. To this end, pragmatic yet centralized solutions like the web’s Public Key Infrastructure and ICANN’s DNS system have been implemented. Given that we enjoy the modern web, these solutions are both scalable and practical. But they do not answer a more commercially oriented question of reliability, trustworthiness and other meta characteristics necessary for determining if one wants to do business with the entity. Multi-sided marketplace hosts like eBay have constructed a business model on providing some of this metadata alongside a framework to complete transactions. Judgements about the quality of content, events and businesses are often deeply influenced solely by online ratings from trusted sources . 26 The part of this point relevant to Cardano is a question of centralization of reputation. One of our goals for Cardano is to provide a financial stack for the developing world. A key to this effort is the ability to establish trust with actors one has never met. If a single entity or a consortium of entities control who is labeled good or bad, not an organic process derived from actual interactions in the community as a whole, then these entities could arbitrarily blacklist anyone for any perceived sin. This power is against our values as a project and defeats the broader point of using a cryptocurrency. Fortunately, the same mechanisms used in voting for treasury ballots, adding sources to a list of trusted data feeds and forking a protocol can be reused to establish a reputation space. It is an open area of research and our hope is to provide an overlay protocol for a decentralized reputation web of trust in 2018-2019 after more foundational elements have been settled. Cryptocurrency Interoperability 25 For digital ledgers on the other hand, proof of reserve has been proposed as a clever way of keeping cryptocurrency only exchanges honest. 26 These rates even impact the creation of content itself. See this interest story on how Rotten Tomatoes has impacted the movie industry. WHY WE ARE BUILDING CARDANO  Creative Commons Attribution 4.0 International License Page 32 of 44