After the global financial crisis in 2008, the world has been putting more effort into tightening banking and financial activities with stricter regulations. However, the effectiveness of this policy has remained controversial as many people believe that policymakers should promote freedom and transparency by empowering the public to directly interfere and change the system for the public interest. This article attempts to synthesize and analyze available information with a focus on the role of the blockchain, a financial tool that can potentially play an important role in the sustainable development of the global economy.
There is a wide spectrum of blockchain applications ranging from cryptocurrency, financial services, risk management, internet of things to public and social services. Although a number of studies focus on using the blockchain technology in various application aspects, there is no comprehensive survey on the blockchain technology in both technological and application perspectives. To fill this gap, we conduct a comprehensive survey on the blockchain technology. In particular, this paper gives the blockchain taxonomy, introduces typical blockchain consensus algorithms, reviews blockchain applications and discusses technical challenges as well as recent advances in tackling the challenges. Moreover, this paper also points out the future directions in the blockchain technology.
Blockchain technology enables the creation of decentralized currencies, self-executing digital contracts (smart contracts) and intelligent assets that can be controlled over the Internet (smart property). The blockchain also enables the development of new governance systems with more democratic or participatory decision-making, and decentralized (autonomous) organizations that can operate over a network of computers without any human intervention. These applications have led many to compare the blockchain to the Internet, with accompanying predictions that this technology will shift the balance of power away from centralized authorities in the field of communications, business, and even politics or law.
Bitcoin that is often called the first cryptocurrency has enjoyed a huge success with the capital market reaching 10 billion dollars in 2016. The blockchain is the core mechanism for the Bitcoin. Blockchain was first proposed in 2008 and implemented in 2009. Blockchain can be regarded as a public ledger, in which all committed transactions are stored in a chain of blocks. Blockchain can work in a decentralized environment, which is enabled by integrating several core technologies such as cryptographic hash, digital signature (based on asymmetric cryptography) and distributed consensus mechanism.
The blockchain is highly appraised and endorsed for its decentralized infrastructure and peer-to-peer nature. However, many types of research about the blockchain are shielded by Bitcoin. But blockchain can be applied to a variety of fields far beyond Bitcoin. Blockchain has shown its potential for transforming the traditional industry with its key characteristics: decentralization, persistency, anonymity, and auditability. Nowadays smart contract is developing fast, many smart contract applications are proposed. However, as there are still many defects and limits in smart contract languages, many innovative applications are hard to implement currently.