A blockchain – originally block chain – is a distributed database that maintains a continuously growing list of records, called blocks, secured from tampering and revision. Each block contains a timestamp and a link to a previous block. By design, blockchains are inherently resistant to modification of the data — once recorded, the data in a block cannot be altered retroactively. Through the use of a peer-to-peer network and a distributed timestamping server, a blockchain database is managed autonomously. Blockchains are “an open, distributed ledger that can record transactions between two parties efficiently and in a verifiable and permanent way. The ledger itself can also be programmed to trigger transactions automatically.”
ledger: a ledger is a book in which a company or organization writes down the amounts of money it spends and receives. 分类账
verifiable: Something that is verifiable can be proved to be true or genuine. 可证实的
如何保证 block 数据不能篡改？
Blockchain formation. The main chain (black) consists of the longest series of blocks from the genesis block (green) to the current block. Orphan blocks (purple) exist outside of the main chain.
Blockchains are secure by design and an example of a distributed computing system with high byzantine fault tolerance. Decentralized consensus can therefore be achieved with a blockchain. This makes blockchains suitable for the recording of events, medical records, and other records management activities, identity management, transaction processing, and documenting provenance.
byzantine: if you describe a system or process as byzantine, you are criticizing it because it seems complicated or secretive. 复杂的; 秘密的
provenance: The provenance of something is the place that it comes from or that it originally came from. 出处
The first blockchain was conceptualised by Satoshi Nakamoto in 2008 and implemented the following year as a core component of the digital currency bitcoin, where it serves as the public ledger for all transactions. The invention of the blockchain for bitcoin made it the first digital currency to solve the double spending problem, without the use of a trusted authority or central server. The bitcoin design has been the inspiration for other applications.
Satoshi Nakamoto is the name used by the unknown person or persons who designed bitcoin and created its original reference implementation. As a part of the implementation, he also devised the first blockchain database. In the process he was the first to solve the double spending problem for digital currency. He was active in the development of bitcoin up until December 2010.