1、Distributed Ledger T echnology: beyond block chain A report by the UK Government Chief Scientific Adviser3 Contents Foreword .4 Executive Summary and Recommendations .5 Definitions .17 Chapter 1: Vision 21 Chapter 2: Technology.33 Case study Research and horizon scanning 37 Chapter 3: Governance and
2、 Regulation 41 Chapter 4: Security and Privacy .47 Chapter 5: Disruptive Potential 53 Case study Diamonds .56 Case study Corporate actions 58 Case study SETLing transactions 60 Chapter 6: Applications in Government 65 Chapter 7: Global Perspectives 73 Case study European energy retail market .76 Cas
3、e study Estonian block chains transform paying, trading and signing .80 References 84 Acknowledgements .87 A short video has been made to accompany this report which can be viewed at: https:/youtu.be/4sm5LNqL5j04 Foreword The progress of mankind is marked by the rise of new technologies and the huma
4、n ingenuity they unlock. In distributed ledger technology, we may be witnessing one of those potential explosions of creative potential that catalyse exceptional levels of innovation. The technology could prove to have the capacity to deliver a new kind of trust to a wide range of services. As we ha
5、ve seen open data revolutionise the citizens relationship with the state, so may the visibility in these technologies reform our financial markets, supply chains, consumer and business-to-business services, and publicly-held registers. We know there will be challenges as Distributed Ledgers mature a
6、nd disrupt how we think about and store data. The UK is in a unique position to explore those challenges and help maximise the benefits to our public services and our economy. We already have world-class digital capability, innovative financial services, a strong research community and growing priva
7、te sector expertise. It is vital that our key assets including the Alan Turing Institute, Open Data Institute and the Digital Catapult work together with the private sector and with international partners to unlock the full potential of this technology. We are both, therefore, delighted to be jointl
8、y leading efforts in this area, and look forward to working with other departments on seizing the opportunity as well as understanding how its use can be implemented for the benefit of UK citizens and the economy. THE RT HON MATTHEW HANCOCK MP Minister for the Cabinet Office and Paymaster General TH
9、E RT HON ED VAIZEY MP Minister of State for Culture and The Digital Economy5 Executive Summary and Recommendations Introduction Algorithms that enable the creation of distributed ledgers are powerful, disruptive innovations that could transform the delivery of public and private services and enhance
10、 productivity through a wide range of applications. Ledgers have been at the heart of commerce since ancient times and are used to record many things, most commonly assets such as money and property. They have moved from being recorded on clay tablets to papyrus, vellum and paper. However, in all th
11、is time the only notable innovation has been computerisation, which initially was simply a transfer from paper to bytes. Now, for the first time algorithms enable the collaborative creation of digital distributed ledgers with properties and capabilities that go far beyond traditional paper-based led
12、gers. A distributed ledger is essentially an asset database that can be shared across a network of multiple sites, geographies or institutions. All participants within a network can have their own identical copy of the ledger. Any changes to the ledger are reflected in all copies in minutes, or in s
13、ome cases, seconds. The assets can be financial, legal, physical or electronic. The security and accuracy of the assets stored in the ledger are maintained cryptographically through the use of keys and signatures to control who can do what within the shared ledger. Entries can also be updated by one
14、, some or all of the participants, according to rules agreed by the network. Underlying this technology is the block chain, which was invented to create the peer-to-peer digital cash Bitcoin in 2008. Block chain algorithms enable Bitcoin transactions to be aggregated in blocks and these are added to
15、 a chain of existing blocks using a cryptographic signature. The Bitcoin ledger is constructed in a distributed and permissionless fashion, so that anyone can add a block of transactions if they can solve a new cryptographic puzzle to add each new block. The incentive for doing this is that there is
16、 currently a reward in the form of twenty five Bitcoins awarded to the solver of the puzzle for each block. Anyone with access to the internet and the computing power to solve the cryptographic puzzles can add to the ledger and they are known as Bitcoin miners. The mining analogy is apt because the
17、process of mining Bitcoin is energy intensive as it requires very large computing power. It has been estimated that the energy requirements to run Bitcoin are in excess of 1GW and may be comparable to the electricity usage of Ireland. Bitcoin is an online equivalent of cash. Cash is authenticated by
18、 its physical appearance and characteristics, and in the case of banknotes by serial numbers and other security devices. But in the case of cash there is no ledger that records transactions and there is a problem with forgeries of both coins and notes. In the case of Bitcoins, the ledger of transact
19、ions ensures their authenticity. Both coins and Bitcoins need to be stored securely in real or virtual wallets respectively and if these are not looked after properly, both coins and Bitcoins can be stolen. A fundamental difference between conventional currency and Bitcoins is that the former are is
20、sued by central banks, and the latter are issued in agreed 6 amounts by the global collaborative endeavour that is Bitcoin. Cash as a means of exchange and commerce dates back millennia and in that respect there is a lineage that links cowrie shells, hammered pennies and Bitcoin. But this report is
21、not about Bitcoin. It is about the algorithmic technologies that enable Bitcoin and their power to transform ledgers as tools to record, enable and secure an enormous range of transactions. So the basic block chain approach can be modified to incorporate rules, smart contracts, digital signatures an
22、d an array of other new tools. Distributed ledger technologies have the potential to help governments to collect taxes, deliver benefits, issue passports, record land registries, assure the supply chain of goods and generally ensure the integrity of government records and services. In the NHS, the t
23、echnology offers the potential to improve health care by improving and authenticating the delivery of services and by sharing records securely according to exact rules. For the consumer of all of these services, the technology offers the potential, according to the circumstances, for individual cons
24、umers to control access to personal records and to know who has accessed them. Existing methods of data management, especially of personal data, typically involve large legacy IT systems located within a single institution. To these are added an array of networking and messaging systems to communica
25、te with the outside world, which adds cost and complexity. Highly centralised systems present a high cost single point of failure. They may be vulnerable to cyber- attack and the data is often out of sync, out of date or simply inaccurate. In contrast, distributed ledgers are inherently harder to at
26、tack because instead of a single database, there are multiple shared copies of the same database, so a cyber-attack would have to attack all the copies simultaneously to be successful. The technology is also resistant to unauthorised change or malicious tampering, in that the participants in the net
27、work will immediately spot a change to one part of the ledger. Added to this, the methods by which information is secured and updated mean that participants can share data and be confident that all copies of the ledger at any one time match each other. But this is not to say that distributed ledgers
28、 are invulnerable to cyber-attack, because in principle anyone who can find a way to legitimately modify one copy will modify all copies of the ledger. So ensuring the security of distributed ledgers is an important task and part of the general challenge of ensuring the security of the digital infra
29、structure on which modern societies now depend. Governments are starting to apply distributed ledger technologies to conduct their business. The Estonian government has been experimenting with distributed ledger technology for a number of years using a form of distributed ledger technology known as
30、Keyless Signature Infrastructure (KSI), developed by an Estonian company, Guardtime. KSI allows citizens to verify the integrity of their records on government databases. It also appears to make it impossible for privileged insiders to perform illegal acts inside the government networks. This abilit
31、y to assure citizens that their data are held securely and accurately has helped Estonia to launch digital services such as e-Business Register and e-Tax. These reduce the 7 administrative burden on the state and the citizen. Estonia is one of the Digital 5 or D5 group of nations, of which the other
32、 members are the UK, Israel, New Zealand and South Korea. There are opportunities for the UK to work with and learn from these and other like-minded governments in the implementation of block chain and related technologies. The business community has been quick to appreciate the possibilities. Distr
33、ibuted ledgers can provide new ways of assuring ownership and provenance for goods and intellectual property. For example, Everledger provides a distributed ledger that assures the identity of diamonds, from being mined and cut to being sold and insured. In a market with a relatively high level of p
34、aper forgery, it makes attribution more efficient, and has the potential to reduce fraud and prevent blood diamonds from entering the market. An important challenge for this new set of technologies is communication of its significance to policymakers and to the public this is one of the important pu
35、rposes of this report. The first difficulty in communication is the strong association of block chain technology with Bitcoin. Bitcoin is a type of cryptocurrency, so called because cryptography underpins the supply and tracking of the currency. Bitcoin creates suspicion amongst citizens and governm
36、ent policymakers because of its association with criminal transactions and dark web trading sites, such as the now defunct Silk Road. But digital cryptocurrencies are of interest to central banks and government finance departments around the world which are studying them with great interest. This is
37、 because the electronic distribution of digital cash offers potential efficiencies and, unlike physical cash, it brings with it a ledger of transactions that is absent from physical cash. The second difficulty in communication is the bewildering array of terminology. This terminology is clarified by
38、 Simon Taylor who has provided a set of definitions at the end of this summary. A particular term that can cause confusion is distributed, which can lead to the misconception that because something is distributed there is therefore no overall controlling authority or owner. This may or may not be th
39、e case it depends on the design of the ledger. In practice, there is a broad spectrum of distributed ledger models, with different degrees of centralisation and different types of access control, to suit different business needs. These may be unpermissioned ledgers that are open to everyone to contr
40、ibute data to the ledger and cannot be owned; or permissioned ledgers that may have one or many owners and only they can add records and verify the contents of the ledger. The key message is that, by fully understanding the technology, government and the private sector can choose the design that bes
41、t fits a particular purpose, balancing security and central control with the convenience and opportunity of sharing data between institutions and individuals. As with most new technologies, the full extent of future uses and abuses is only visible dimly. And in the case of every new technology the q
42、uestion is not whether the technology is in and of itself a good thing or a bad thing. The questions are: what application of the technology? for what purpose? and applied in what way and with what safeguards?8 To help answer these questions, the Government Office of Science established a senior gro
43、up of experts from business, government and academia to assess the opportunities for distributed ledgers to be used within government and the private sector, and to determine what actions government and others need to take to facilitate the beneficial use of distributed ledger technology and to avoi
44、d possible harms. The aim was to decrypt the terminology behind the technology for policy audiences and provide policymakers with the vision and evidence to help them to decide where action is necessary, and how best to deploy it. In summary, distributed ledger technology provides the framework for
45、government to reduce fraud, corruption, error and the cost of paper-intensive processes. It has the potential to redefine the relationship between government and the citizen in terms of data sharing, transparency and trust. It has similar possibilities for the private sector. This executive summary
46、now sets out the eight main recommendations from our work. These are presented in the context of a summary of the key points from the seven chapters of evidence which cover vision, technology, governance, privacy and security, disruptive potential, applications and global perspective. The chapters h
47、ave been written by experts in distributed ledger technology in a style that should be accessible to non-experts. I am extremely grateful to these experts for their guidance and thoughtful contributions. Mark Walport, Chief Scientific Adviser to HM Government, December 20159 Vision Distributed ledge
48、rs offer a range of benefits to government and to other public and private sector organisations. As their name implies, they can be distributed extremely widely in a precisely controlled fashion. They are highly efficient because changes by any participant with the necessary permission to modify the
49、 ledger are immediately reflected in all copies of the ledger. They can be equally robust in rejecting unauthorised changes, so corrupting the ledger is extremely difficult. However, distributed ledgers should not be seen as an end in themselves. It is only when they have other applications such as smart contracts layered on top on them, that their full potential can be realised. The first role for government in supporting the development of distributed ledgers is to develop a clear vision of how this technology can improve the way go
