CONCLUDING REMARKS

In this chapter, we analyzed the current Bitcoin ecosystem. Although Bitcoin does not truly solve all of the challenges faced by previously proposed digital currencies, Bitcoin grew to witness a wider adoption and attention than any other digital currency proposed to date. At the time of writing, Bitcoin holds the largest market share among all existing digital currencies, with a market cap exceeding $3 billion [52]. As described in this chapter, there are numerous businesses, exchange platforms, and wallets that are currently built around the Bitcoin ecosystem.

Unlike previous electronic cash proposals, Bitcoin's proposal was rather straightforward, relying on basic cryptographic constructs, such as hash functions and digital signatures. The release of the proof of concept implementation of Bitcoin shortly after the dissemination of the white paper was extremely timely and important for the subsequent growth of Bitcoin. The working implementation confirmed that, unlike previous proposals, the system is clearly feasible/workable, and scales to a large number of nodes.

We believe that an additional reason that led to the sustainability and growth of the Bitcoin system was the ability of the developers to assimilate research results from the security community and integrate them swiftly within the development of released client implementations. In the remaining chapters, we discuss in detail the various security and privacy provisions of Bitcoin and its underlying blockchain— effectively capturing eight years of thorough research on these subjects in the Bitcoin community.

We however note that a large number of centralized services currently host Bitcoin and control a considerable share in the Bitcoin market. Even worse, Bitcoin developers retain privileged rights in conflict resolution and maintenance of the clients’ software. These entities altogether can decide the fate of the entire Bitcoin system, thus bypassing the will, rights, and computing power of the multitude of users that populate the network.

Currently, almost every financial system is controlled by governments and banks; Bitcoin substitutes these powerful entities with other entities such as IT developers and owners of mining pools. While current systems are governed by means of transparent and thoroughly investigated legislations, vital decisions in Bitcoin are taken through the exchange of opinions among developers and mining pool owners on mailing lists. In this sense, Bitcoin finds itself now in unfamiliar territory: on one hand, the Bitcoin ecosystem is far from being decentralized; on the other hand, the increasing centralization of the system does not abide by any transparent regulations/legislations. This could, in turn, lead to severe consequences for the fate and reputation of the system.