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自顶向下101

关于本课程

  • 主讲人:李叔禄
  • 以Ethereum为例,生态最好的公链
  • 采用自顶向下方法
    • 区块链应用
    • Solidity代码
    • 以太坊源码
    • p2p协议
  • 不仅是传递知识,更是传递思维
  • 本次思维:封装
  • 希望招募同学来共同构建课程

密码学

Hash

任意长度的二进制字节→固定长度的字符串
  • preimage resistance
    • given y, you can’t find any x such that hash(x) == y
  • 2nd preimage resistance
    • given x, y, such that hash(x) == y, can’t find x’ ≠ x, where hash(x’)==y
  • collision resistance ( harder )
    • nobody can find any x, z such that x ≠ z, where hash(x) == hash(z)

ECC: Elliptic Curve Cryptography

  • Private Key → Public Key
  • Sign(Message, Private Key) → Signature
  • Verify(Message, Signature, Public Key) → True or False
Elliptic Curve
  • a line will intersect with Elliptic curve on 3 points
  • A + B, A * b, A / b ✅
  • A * B, A + b ❌
  • traits of elliptic curve remain when modulo
Secp256k1
Where the name comes from
  • Sec: Standards For Efficient Cryptography
  • 256: length of p
  • p: the mod factor
  • k: inventor of ECC Koblitz, here meaning a selected set of curves
  • 1:
  • is a prime number
  • 30% more performant than unoptimized curves
PKC
: generator point, 32 byte x coord, 32 byte y coord = 64 B ⇒ 32B x coord + 1 bit
: private key. 256 bit scalar
: public key.
Signature
  • Signing:
    • user has private key , now generate random secret (32 bytes)
  • Verify: Verifier receives (message), (public key which eq ), &
  • Security:
    • can’t calculate because R is one-way

钱包

什么是钱包?

  • 个人认为,更好的词汇是“私钥保险库”
  • 保管你的私钥

Metamask

  • 注意安装包的来源!

Claim Your ETH

 

区块链网络

  • Ethereum Mainnet
    • Goerli Test Net
    • Ropsten: Deprecated
  • Polygon
  • Avalanche

转账

Gas Fee

  • 为什么需要 Gas Fee?
  • 最简单的理解方式:免费的网络,服务器的账单谁来付?

Transaction

  • State → Transaction → State
  • Pending… waiting for the block to be confirmed
  • FrontRunning: The Dark Forest

ENS

Ethereum Naming Service

  • Domain Naming Service
  • String → Address

Register Your ENS

Etherscan

最后:怎么进一步学习

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