Made changes to ch01.asciidoc

ch01.asciidoc

@@ -11,7 +11,7 @@ Unlike traditional currencies, bitcoins are entirely virtual. There are no physi
 
 Bitcoin is a distributed, peer-to-peer system. As such there is no "central" server or point of control. Bitcoins are created through a process called "mining," which involves looking for a solution to a difficult problem. Any participant in the bitcoin network (i.e., anyone using a device running the full bitcoin protocol stack) may operate as a miner, using their computer's processing power to attempt to find solutions to this problem. Every 10 minutes on average, someone is able to validate the transactions of the past 10 minutes and is rewarded with brand new bitcoins. Essentially, bitcoin mining decentralizes the currency-issuance and clearing functions of a central bank and replaces the need for any central bank with this global competition. 
  
-((("mining","algorithms regulating")))The bitcoin protocol includes built-in algorithms that regulate the mining function across the network.  The difficulty of the processing task that miners must perform—to successfully record a block of transactions for the bitcoin network—is adjusted dynamically so that, on average, someone succeeds every 10 minutes regardless of how many miners (and CPUs) are working on the problem at any moment.  ((("bitcoin","rate of issuance")))The protocol also halves the rate at which new bitcoins are created every 4 years, and limits the total number of bitcoins that will be created to a fixed total of 21 million coins. The result is that the number of bitcoins in circulation closely follows an easily predictable curve that reaches 21 million by the year 2140.  Due to bitcoin's diminishing rate of issuance, over the long term, the bitcoin currency is deflationary. Furthermore, bitcoin cannot be inflated by "printing" new money above and beyond the expected issuance rate.
+((("mining","algorithms regulating")))The bitcoin protocol includes built-in algorithms that regulate the mining function across the network.  The difficulty of the processing task that miners must perform—to successfully record a block of transactions for the bitcoin network—is adjusted dynamically so that, on average, someone succeeds every 10 minutes regardless of how many miners (and CPUs) are working on the task at any moment.  ((("bitcoin","rate of issuance")))The protocol also halves the rate at which new bitcoins are created every four years, and limits the total number of bitcoins that will be created to a fixed total of 21 million coins. The result is that the number of bitcoins in circulation closely follows an easily predictable curve that reaches 21 million by the year 2140.  Due to bitcoin's diminishing rate of issuance, over the long term, the bitcoin currency is deflationary. Furthermore, bitcoin cannot be inflated by "printing" new money above and beyond the expected issuance rate.
 
 Behind the scenes, bitcoin is also the name of the protocol, a network, and a distributed computing innovation. The bitcoin currency is really only the first application of this invention. As a developer, I see bitcoin as akin to the Internet of money, a network for propagating value and securing the ownership of digital assets via distributed computation. There's a lot more to bitcoin than first meets the eye. 
 
@@ -20,21 +20,21 @@ In this chapter we'll get started by explaining some of the main concepts and te
 .Digital Currencies Before Bitcoin
 ****
 
-((("bitcoin","precursors to")))The emergence of viable digital money is closely linked to developments in cryptography. This is not surprising when one considers the fundamental challenges involved with using bits to represent value that can be exchanged for goods and services. Two fundamental questions for anyone accepting digital money are:
+((("bitcoin","precursors to")))The emergence of viable digital money is closely linked to developments in cryptography. This is not surprising when one considers the fundamental challenges involved with using bits to represent value that can be exchanged for goods and services. Two basic questions for anyone accepting digital money are:
 
 1.     Can I trust the money is authentic and not counterfeit?
 2.     Can I be sure that no one else can claim that this money belongs to them and not me? (Aka the((("double-spend problem"))) “double-spend” problem.)
  
-((("counterfeiting")))((("crypto-currency","counterfeiting")))Issuers of paper money are constantly battling the counterfeiting problem by using increasingly sophisticated papers and printing technology.  Physical money addresses the double-spend issue easily because the same paper note cannot be in two places at once. Of course, conventional money is also often stored and transmitted digitally. In this case the counterfeiting and double-spend issues are handled by clearing all electronic transactions through central authorities that have a global view of the currency in circulation. For digital money, which cannot take advantage of esoteric inks or holographic strips,((("cryptography"))) cryptography provides the basis for trusting the legitimacy of a user’s claim to value.  Specifically, cryptographic digital signatures enable a user to sign a digital asset or transaction proving the ownership of that asset. With the appropriate architecture, digital signatures also can be used to address the double-spend issue.
+((("counterfeiting")))((("crypto-currency","counterfeiting")))Issuers of paper money are constantly battling the counterfeiting problem by using increasingly sophisticated papers and printing technology.  Physical money addresses the double-spend issue easily because the same paper note cannot be in two places at once. Of course, conventional money is also often stored and transmitted digitally. In these cases, the counterfeiting and double-spend issues are handled by clearing all electronic transactions through central authorities that have a global view of the currency in circulation. For digital money, which cannot take advantage of esoteric inks or holographic strips,((("cryptography"))) cryptography provides the basis for trusting the legitimacy of a user’s claim to value.  Specifically, cryptographic digital signatures enable a user to sign a digital asset or transaction proving the ownership of that asset. With the appropriate architecture, digital signatures also can be used to address the double-spend issue.
 
 When cryptography started becoming more broadly available and understood in the late 1980s, many researchers began trying to use cryptography to build digital currencies. These early digital currency projects issued digital money, usually backed by a national currency or precious metal such as gold.
 
-Although these earlier digital currencies worked, they were centralized and, as a result, they were easy to attack by governments and hackers. Early digital currencies used a central clearinghouse to settle all transactions at regular intervals, just like a traditional banking system. Unfortunately, in most cases these nascent digital currencies were targeted by worried governments and eventually litigated out of existence. Some failed in spectacular crashes when the parent company liquidated abruptly. To be robust against intervention by antagonists, whether legitimate governments or criminal elements, a de-centralized digital currency was needed to avoid a single point of attack. Bitcoin is such a system, completely decentralized by design, and free of any central authority or point of control that can be attacked or corrupted.
+Although these earlier digital currencies worked, they were centralized and, as a result, they were easy to attack by governments and hackers. Early digital currencies used a central clearinghouse to settle all transactions at regular intervals, just like a traditional banking system. Unfortunately, in most cases these nascent digital currencies were targeted by worried governments and eventually litigated out of existence. Some failed in spectacular crashes when the parent company liquidated abruptly. To be robust against intervention by antagonists, whether legitimate governments or criminal elements, a decentralized digital currency was needed to avoid a single point of attack. Bitcoin is such a system, completely decentralized by design, and free of any central authority or point of control that can be attacked or corrupted.
 
 Bitcoin represents the culmination of decades of research in cryptography and distributed systems and includes four key innovations brought together in a unique and powerful combination. Bitcoin consists of:
  
 * A decentralized peer-to-peer network (the bitcoin protocol)
-* A public transaction ledger (the blockchain)
+* A public transaction ledger (the block chain)
 * A decentralized mathematical and deterministic currency issuance (distributed mining)
 * A decentralized transaction verification system (transaction script)
 
@@ -42,7 +42,7 @@ Bitcoin represents the culmination of decades of research in cryptography and di
 
 === History of Bitcoin
 
-((("bitcoin","development of")))((("Nakamoto, Satoshi")))Bitcoin was invented in 2008 by Satoshi Nakamoto with the publication of a paper titled((("Bitcoin: A Peer-to-Peer Electronic Cash System. (Nakamoto)"))) "Bitcoin: A Peer-to-Peer Electronic Cash System." Satoshi Nakamoto combined several prior inventions such as((("b-money")))((("HashCash"))) b-money and HashCash to create a completely decentralized electronic cash system that does not rely on a central authority for currency issuance or settlement and validation of transactions. The key innovation was to use a distributed computation system (called a((("Proof-Of-Work algorithm"))) "Proof-Of-Work" algorithm) to conduct a global "election" every 10 minutes, allowing the de-centralized network to arrive at _consensus_ about the state of transactions. This elegantly solves the issue of double-spend where a single currency unit can be spent twice. Previously, the double-spend problem was a weakness of digital currency and was addressed by clearing all transactions through a central clearinghouse. 
+((("bitcoin","development of")))((("Nakamoto, Satoshi")))Bitcoin was invented in 2008 with the publication of a paper titled((("Bitcoin: A Peer-to-Peer Electronic Cash System. (Nakamoto)"))) "Bitcoin: A Peer-to-Peer Electronic Cash System," written under the alias of Satoshi Nakamoto. Nakamoto combined several prior inventions such as((("b-money")))((("HashCash"))) b-money and HashCash to create a completely decentralized electronic cash system that does not rely on a central authority for currency issuance or settlement and validation of transactions. The key innovation was to use a distributed computation system (called a((("proof-of-work algorithm"))) "proof-of-work" algorithm) to conduct a global "election" every 10 minutes, allowing the de-centralized network to arrive at _consensus_ about the state of transactions. This elegantly solves the issue of double-spend where a single currency unit can be spent twice. Previously, the double-spend problem was a weakness of digital currency and was addressed by clearing all transactions through a central clearinghouse. 
 
 ((("bitcoin network","origin of")))The bitcoin network started in 2009, based on a reference implementation published by Nakamoto and since revised by many other programmers. The distributed computation that provides security and resilience for bitcoin has increased exponentially, and now exceeds that combined processing capacity of the world's top super-computers. Bitcoin's total market value is estimated at between 5 and 10 billion US dollars, depending on the dollar/bitcoin exchange rate. The largest transaction processed so far by the network was 150 million US dollars, transmitted instantly and processed without any fees.