依托一个区块链技术总体框架，以应对两个问题（区块链不可能三角、隐私保护）为背景，通过分析典型案例，本报告对2019年区块链技术在节点通信层、账本数据层、共识协议层、智能合约层、密码算法层、身份管理层、隐私保护层乃至链外扩容等的发展情况进行全面回顾。通过回顾可以看出，在过去一年，区块链技术可谓齐头并进，全面发展，而且中国在此过程中做出了可圈可点的贡献。立足过去，展望未来，对区块链技术的发展趋势可做如下研判：区块链技术的发展没有在短期内中止的迹象，在应对不可能三角形、提供隐私保护等方面将出现更多方案，未来可期；充分掌握现有手段并加以新的运用，将是推动区块链技术进步的重要手段；密码学技术对区块链的重要性日益凸显，定将成为区块链领域的必争之地。
Based on an analytical framework，and has taken the solutions of blockchain impossible triangle and privacy protection as the background，this report makes a panoramic review of blockchain technology after 2019. It covers the developments in node communication layer，ledger data layer，consensus protocol layer，smart contract layer，cryptographic layer，identity management layer，privacy protection layer and scaling solution outside of chain. This review unvails the fact that significant and thorough progress has been made in the past year，and notably China has contributed a lot during this period. It can be anticipated that the blockchain technology will continue to progress from now on，and more solutions can be seen in the future. It is important to invent new combinations of existing technologies to make advance in the blockchain technology. Cryptography will gain more importance and will be the next big battlefield in the future for blockchain technology.
