Chapter 4 edits
I am not a programmer and have only used Git Hub to submit comments and edits for this book. As a result I am not familiar with pull requests and how to use them. Please forgive my ignorance (proofreading books is much easier with something like Google Docs or MS Word..). Serhack asked me to work on Chapters 4-6 as the hired proofreader is currently working on 3. I am just going to copy/paste chapter 4 below and make my edits in **_bold italics._** I hope this helps...

Chapter 4
Mining and Proof of Work

At the beginning of this ebook **_we talked about the double spending problem._** **_Avoiding double spending_** is a priority for several cryptocurrencies. **_In this chapter we will look at how Monero avoids this problem._**

**_An essential function of the decentralized blockchain is it's ability to_** confirm that each input in the transaction could be trusted. In order to check that, **_the blockchain use algorithms to find_** "consensus", meaning each node will **_agree on and_** provide its confirmation for the transaction.

What is mining?

Mining is the process by which transactions are verified and added to the public ledger, known as the blockchain, and also the means through which new monero are released.  Anyone with access to the internet and suitable hardware can participate in mining. The mining process involves compiling recent transactions into blocks and trying to solve a computationally difficult puzzle. The participant who first solves the puzzle gets to place the next block on the block chain and claim the rewards. The rewards, which incentivize mining, are both the transaction fees associated with the transactions compiled in the block**_,_** as well as newly released Monero. **_Moved from earlier in paragraph:_** A lot of people would like to mark that mining is not the process of creation of coins. **_Beyond confirming transactions and creating new monero, mining also secures the decentralized Monero network. The more people using their computer hardware to mine monero, the more secure the network becomes. Even you can mine Monero!_**

Coin Emission

Monero main emission curve will issue about 18.4 million coins to be mined in approximately 8 years from its creation. (more precisely 18.132 Million coins by ca. end of May 2022) After that, a constant "tail emission" of 0.6 XMR per 2-minutes block (modified from initially equivalent 0.3 XMR per 1-minute block) will create a sub-1% perpetual inflation starting with 0.87% yearly inflation around May 2022) to prevent the lack of incentives for miners once a currency is not mineable anymore.

**_This "built-in inflation" feature is often overlooked or misunderstood. It is also the one of the many features that makes Monero more suitable to replace fiat cash than any other cryptocurrency. Here is why: In both local and global fiat economies, mild, predictable inflation is actually a good thing. Mild, predictable inflation 1) ensures demand for products (I want to buy it now when it will be cheaper than later), and 2) protects against rapid deflation (the value of my money is quickly dropping). A sub-1% perpetual inflation is arguably more secure, stable, and protective than any current or historical examples of fiat currency._**

Despite to others cryptocurrencies, Monero has infinite supply.
Eligiptiaran Proof of Work

A proof of work is a piece of data which is difficult (costly, time consuming) to produce but easy for others to verify and which satisfies certain requirements. Producing a proof of work can be a random process with low probability so that a lot of trial and error is required on average before a valid proof of work is generated. In order for a block to be accepted by network participants, miners must complete a proof of work which covers all of the data in the block. The difficulty of this work is adjusted so as to limit the rate at which new blocks can be generated by the network to one every 10 minutes. Due to the very low probability of successful generation, this makes it unpredictable which worker computer in the network will be able to generate the next block.

Monero is powered strictly by Proof of Work. It employs a mining algorithm that has the potential to be efficiently tasked to billions of existing devices (any modern x86 CPU and many GPUs). Monero uses the CryptoNight Proof of Work (PoW) algorithm, which is designed for use in ordinary CPUs and GPUs.

The smart mining feature allows transparent CPU mining on the user's computer, far from the de facto centralization of mining farms and pool mining, pursuing Satoshi Nakamoto's original vision of a true P2P currency. **_As a result, it makes the currency more accessible to the average person and helps secure the network at the same time._**

ASIC-resistant algorithm

An ASIC (Application Specific Integrated Circuit) is custom mining hardware that is specialized for a particular use. For example, Bitcoin ASICs are specialized to mine cryptocurrencies utilizing a SHA256 hash algorithm. Due to the fact that they are designed for a specific use, they will typically have a large performance advantage over hardware that is intended for general-purpose use like CPUs, GPUs, and even FPGAs. Thus, any newly developed ASIC will obtain a significant majority of the network hashrate and introduce centralization.

The Monero code was forked from the CryptoNote reference implementation. In the CryptoNote whitepaper (https://cryptonote.org/whitepaper.pdf), one of the identified deficiencies of Bitcoin is **_how it utilizes_** Proof of Work due to its centralizing nature, as we will discuss below.

In order to create a more egalitarian mining network and foster decentralization, the original CryptoNote developers created the Cryptonight Proof of Work function to "close the gap between CPU (majority) and GPU/FPGA/ASIC (minority) miners." While the CryptoNote authors admit that "It is appropriate that some users can have a certain advantage over others," they propose that "their investments should grow at least linearly with the power." Thus, it is recognized that ASICs may be an inevitable development for any Proof of Work. We also concede that ASICs may be inevitable, but we feel that any transition to an ASIC-dominated network needs to be as egalitarian as possible in order to foster decentralization.

The drawback of Bitcoin's (SHA256) proof-of-work system is the easy migration from CPUs to GPUs, to FPGAs, and finally to ASICs, where each step came with huge efficiency improvements. Thus, there is a large gap between CPU mining and ASIC mining, which resulted in ASICs being the only viable way to mine. In essence, this causes centralization, because only those with access to specialized hardware (ASICs) are still able to mine, and these typically come from one or very few manufacturers. Cryptonight (Monero's proof-of-work system) intends to close the gap between CPU and GPU, FPGA, and ASIC mining by using a proof-of-work system that is memory bound over a moderate amount of memory. As a result, ASICs get significantly more expensive to build. 
**_separated paragraph_**
This proof-of-work system intends to foster egalitarian mining, which yields the following benefits: First, if mining is decentralized (because CPUs and GPUs are still usable for mining), it will be very difficult to pressure miners into not confirming a certain transaction, or otherwise act as a censor to the Monero blockchain. Second, it will lessen the pressure towards centralization of mining in large data centers (as can be seen in Bitcoin). Third, it is quite difficult for governments to regulate companies selling general-purpose hardware (as opposed to companies selling specialized hardware).

Let's further discuss this last point. Specialized hardware will, most likely, only be designed by a few companies. As we can see from Bitcoin, the majority of ASICs are designed and shipped by Bitmain. **_(maybe add some stats here demonstrating the power and scope of Bitmain, to help drive it home to the reader that it's a cause of concern)_**

This creates a single point of failure. For instance, a government could require these ASIC manufacturers to add a "kill-switch" which allows them to shut down a miner remotely or otherwise control it. This threat has the potential to destroy the whole network. In a similar fashion, governments could require miners to have a license to buy and operate ASICs, thereby confining ASICs to a certain group of licensed people. Furthermore, licensing could ultimately lead to blacklisting certain transactions, i.e., governments can require miners to not mine certain transactions, where disobedience would result in miners having their license revoked. By contrast, introducing a license to operate general purpose hardware is probably an infeasible endeavor.

For these reasons, Monero announced to make an hard fork in order to preserve A**_SIC_** **_resistance_**. **_This occured in April 2018 and a drop in network hashrate was revealed, leading many to estimate ASICs had gained control of nearly half the network hashrate. The ASIC companies had economic incentive not to attack the network, but for reasons described above, it was a cause for concern among many in the Monero Community._** Furthermore, in order to maintain its goal of decentralization**_,_** **_deleted and to_** provide a deterrent for ASIC development**_,_** and to protect against unknown or undetectable ASIC development, the Monero team proposes modifying the Cryptonight PoW hash every scheduled fork, twice a year.