區塊鏈筆記
TO READ
Content:
+ 構成 （由小至大）
+ The next Internet Revolution from Juan Benet
+ IPFS
+ References
構成 （由小至大）
有興趣的人請直接看 Reference 更有效率，真的很感謝 陳鍾誠 教授的資訊提供！
1. SHA 256 Hash
2. Block
3. A blockchain
4. Distributed (peers of blockchains)
5. Coin-base transactions
6. Transaction with the signature
1. SHA 256 Hash
A fingerprint of some digital data
組成：Block number + Nonce + Data + previous Hash
一個 block 對應的 hash:
if
前四碼為 0000 => a signed blockif
前四碼不為 0000 => not a signed block
因此 Nonce 的作用是讓 a block 前四碼為 0000
=> 挖礦就是去找到這組 Nonce
3. A blockchain
將 block 串起，每一組 block 包含: Block number, Nonce, Previous hash and (current) Hash
E.g.
A blockchain: 1->2->3->4->5if block 3 data 被竄改=> hash will be changed=> 和 block 4 pre hash 不同=> 被發現遭到串改
4. Distributed (peers of blockchains)
只要比對最新的 hash 即可知道資料是否有被竄改
問題：那如果竄改資料，然後將最新的 hash 改成跟其它 peer 一致的話？
Transaction with the signature 可以解決
5. Coin-base transactions
例如起始金額為100個幣，然後發出去
6. Transaction with the signature
The next Internet Revolution from Juan Benet
單字/句子
- computation (計算)
- in fact = actually
- resilient: able to withstand or recover quickly from difficult conditions
- coordination (協調)
- immutable: unable to be changed
- incentive strucure (激勵架構)
- squint (仔細看)
- it is mandated by the laws of physics (它物理上做得到)
- cease ~= stop
- flaw = defect
- neglect = ignore
重點
- IPFS
- Private money may be one of the most important financial innovations in the short term future
- content addressing: the heart of IPFS
IPFS
- InterPlanetary File System
- A peer-to-peer hypermedia protocol
how IPFS works
- Your file, and all of the blocks within it, is given a unique fingerprint called a
cryptographic hash. - IPFS removes duplications across the network.
- Each network node stores only content it is interested in, plus some indexing information that helps figure out which node is storing what.
- When you look up a file to view or download, you’re asking the network to find the nodes that are storing the content behind that file’s hash.
- A decentralized naming system called IPNS: you don’t need to remember the hash, though — every file can be found by human-readable names. (像DNS一樣的存在)
Reference
[1] 區塊鏈 (比特幣背後的關鍵技術) — 十分鐘系列: https://www.slideshare.net/ccckmit/ss-238688151
[2] Blockchain 101 — A Visual Demo: https://www.youtube.com/watch?v=_160oMzblY8
[3] Blockchain 101 — Part 2 — Public / Private Keys and Signing: https://www.youtube.com/watch?v=xIDL_akeras
[4] 比特幣和區塊鏈到底是啥？礦機挖礦咋回事？李永樂老師講比特幣(1): https://www.youtube.com/watch?v=g_fSistU3MQ
[5] Juan Benet. The next Internet Revolution (2016)
[6] IPFS