Proof of Work Rule - Find a Small Hash Value

This section describes the Proof of Work Rule - Finds a nonce that result a small SHA256 hash value.

The third important Bitcoin Consensus Rule is the Proof of Work Rule: The block hash must meet the cryptographic difficulty requirement. As of 2018, the block hash must be less than or equal to 0x0000000000000000007fffffffffffffffffffffffffffffffffffffffffffff.

Details of the Proof of Work Rule are described below:

As you can see, the main objective of the proof of work rule is to ensure that it will take about 10 minutes to generate, or mine, a new block consistently over time.

As of now, the current Bitcoin difficulty is 3007383866429.732, which can be mapped roughly to a hash target of 0x0000000000000000007fffffffffffffffffffffffffffffffffffffffffffff.

See the "Bitcoin Difficulty Wiki" article at https://en.bitcoin.it/wiki/Difficulty, on how to convert difficulty to hash target.

Table of Contents

 About This Book

 Introduction of Bitcoin

 Bitcoin Blockchain

 Bitcoin Wallet

 Bitcoin Core

 Bitcoin Transaction

 Bitcoin-Qt - Bitcoin Core GUI

 Bitcoin Mining

Bitcoin Consensus Rules

 What Are Bitcoin Consensus Rules

 Controlled Supply Rule - Total of 21M BTC

 Mining Reward Rule - Start with 50 BTC

Proof of Work Rule - Find a Small Hash Value

 Bitcoin Block Data Structure

 Bitcoin Transaction Data Structure

 Bitcoin Blockchain APIs

 Copay - Bitcoin Wallet

 Archived Tutorials

 References

 Full Version in PDF/EPUB