Principles of BTC cryptography

The premise is to master the basic skills of programming ： Array 、 Linked list 、 Binary tree 、 hash function

Reference material : BitCoin and Cryptocurrency Technologies A Comprehensive Introduction、 Ethereum white paper 、 Yellow book 、 Source code 、Solidty file

Used in cryptography hash The function is called Cryptographic hash function, There are two important properties. One is called Collision resistance 

for example xy ,H(x)=H(y) It's called hash collision ( Different inputs , The output is the same )

1. For cryptography hash Functions cannot be artificially made hash Collision

2. For cryptography hash The function is unidirectional , irreversible

For example

When one predicts the limit of the stock market tomorrow , It cannot be disclosed in advance . Because if this person may guide the direction of the rise and fall of the stock market （ Everyone heard him say which stock will rise tomorrow , Everyone buys that stock ）, The best way is for him to write the forecast on a piece of paper , Give this piece of paper to the public trust institution .

Corresponding to the digital world , That's what this is x, Conduct hash(x). Wait until the opening tomorrow , To use this x Judge . because hash（x） It's irreversible , He cannot tamper with the result