New research directions for blockchain networks

区块链技术由于实现了不可变、去中心化、可审计和容错的分布式和复制账本，在过去的十年中引起了工业界和学术界的广泛关注。比特币自2009年推出以来，已发展成为覆盖全球的网络，活跃节点数量和区块大小稳步增长。我们还目睹了新的加密货币和区块链技术在需要安全传输数字资产和分布式存储并保证数据完整性的领域的新应用的大量扩散。然而，该技术的未来发展受到可扩展性和集中化问题的阻碍，这些问题导致了巨大的能源消耗和需要解决的安全漏洞。在两种最流行的加密货币网络比特币和以太坊中，有强大的节点矿池，可以防止其他节点获得挖矿费。一些矿池可能会部署自私的采矿技术，这可能会导致对已经开采的区块进行修剪。这些问题将是我今后五年研究工作的第一部分。区块链技术通过CoAP协议家族成功加入物理网络后，区块链技术在物联网（IoT）中的部署是物联网技术发展的下一步。这一发展给区块链的架构、共识协议和安全性带来了许多需要解决的挑战。我计划在这个五年研究计划的第二部分解决这些挑战。

Blockchain technology has attracted a lot of attention for Industry and Academia in past decade since it implements distributed and replicated ledger which is immutable, decentralized, auditable and fault tolerant. After launch of Bitcoin in 2009 it has grown into network covering the whole globe with steady increase in the number of active nodes and block size. We have also witnessed huge proliferation of new crypto-currencies and new applications of blockchain technology in areas where secure transfer of digital assets and distributed storage with guaranteed data integrity is needed. However future growth of this technology is hindered by scalability and centralization problems which result in huge energy consumption and security vulnerabilities that need to be addressed. In two most popular  crypto-currency networks Bitcoin and Ethereum  there  are powerful mining pools of nodes  which prevent  other nodes from getting mining fees. Some mining pools may deploy selfish mining techniques which can cause pruning of already mined blocks. These problems will be subject of first part of my research work in next five years. Deployment of blockchain technology in Internet of Things (IoT) is next step in development of IoT technology after it has successfully joined physical web through CoAP protocol family. This development brings a plenty of challenges regarding the architecture of blockchain, consensus protocols and security which need to be addressed. I plan to address these challenges in the second part of  this five year research program.