Foreword xxi Introduction xxiii Part I Understanding the Technology 1 Chapter 1 What Is a Cryptocurrency? 3 A New Concept? 3 Leading Currencies in the Field 8 Is Blockchain Technology Just for Cryptocurrencies? 9 Setting Yourself Up as a Bitcoin User 10 Summary 14 Chapter 2 The Hard Bit 15 Hashing 16 Public/Private Key Encryption 21 RSA Cryptography 23 Elliptic Curve Cryptography 28 Building a Simple Cryptocurrency in the Lab 32 Summary 36 Chapter 3 Understanding the Blockchain 39 The Structure of a Block 40 The Block Header 42 Deconstructing Raw Blocks from Hex 47 Applying This to the Downloaded Hex 51 Number of Transactions 55 Block Height 57 Forks 58 The Ethereum Block 61 Summary 65 Chapter 4 Transactions 67 The Concept behind a Transaction 67 The Mechanics of a Transaction 69 Understanding the Mempool 76 Understanding the ScriptSig and ScriptPubKey 77 Interpreting Raw Transactions 79 Extracting JSON Data 81 Analyzing Address History 82 Creating Vanity Addresses 83 Interpreting Ethereum Transactions 85 Summary 86 Chapter 5 Mining 87 The Proof-of-Work Concept 89 The Proof-of-Stake Concept 90 Mining Pools 90 Mining Fraud 92 Summary 93 Chapter 6 Wallets 95 Wallet Types 96 Software Wallets 96 Hardware Wallets 97 Cold Wallets or Cold Storage 98 Why Is Recognizing Wallets Important? 99 Software Wallets 100 Hardware Wallets 100 Paper Wallets 100 The Wallet Import Format (WIF) 101 How Wallets Store Keys 102 Setting Up a Covert Wallet 105 Summary 107 Chapter 7 Contracts and Tokens 109 Contracts 109 Bitcoin 110 Ethereum 110 Tokens and Initial Coin Offerings 112 Summary 116 Part II Carrying Out Investigations 117 Chapter 8 Detecting the Use of Cryptocurrencies 119 The Premises Search 120 A New Category of Search Targets 121 Questioning 124 Searching Online 125 Extracting Private and Public Keys from Seized Computers 130 Commercial Tools 130 Extracting the Wallet File 131 Automating the Search for Bitcoin Addresses 135 Finding Data in a Memory Dump 136 Working on a Live Computer 137 Acquiring the Wallet File 138 Exporting Data from the Bitcoin Daemon 140 Extracting Wallet Data from Live Linux and OSX Systems 144 Summary 145 Chapter 9 Analysis of Recovered Addresses and Wallets 147 Finding Information on a Recovered Address 147 Extracting Raw Data from Ethereum 154 Searching for Information on a Specifi c Address 155 Analyzing a Recovered Wallet 161 Setting Up Your Investigation Environment 161 Importing a Private Key 166 Dealing with an Encrypted Wallet 167 Inferring Other Data 172 Summary 173 Chapter 10 Following the Money 175 Initial Hints and Tips 175 Transactions on Blockchain.info 176 Identifying Change Addresses 177 Another Simple Method to Identify Clusters 181 Moving from Transaction to Transaction 182 Putting the Techniques Together 184 Other Explorer Sites 186 Following Ethereum Transactions 189 Monitoring Addresses 193 Blockonomics.co 193 Bitnotify.com 194 Writing Your Own Monitoring Script 194 Monitoring Ethereum Addresses 196 Summary 197 Chapter 11 Visualization Systems 199 Online Blockchain Viewers 199 Blockchain.info 200 Etherscan.io 201 Commercial Visualization Systems 214 Summary 215 Chapter 12 Finding Your Suspect 217 Tracing an IP Address 217 Bitnodes 219 Other Areas Where IPs Are Stored 226 Is the Suspect Using Tor? 228 Is the Suspect Using a Proxy or a VPN? 229 Tracking to a Service Provider 231 Considering Open-Source Methods 235 Accessing and Searching the Dark Web 237 Detecting and Reading Micromessages 241 Summary 244 Chapter 13 Sniffi ng Cryptocurrency Traffi c 245 What Is Intercept? 246 Watching a Bitcoin Node 247 Sniffi ng Data on the Wire 248 Summary 254 Chapter 14 Seizing Coins 255 Asset Seizure 256 Cashing Out 256 Setting Up a Storage Wallet 259 Importing a Suspect''s Private Key 261 Storage and Security 263 Seizure from an Online Wallet 265 Practice, Practice, Practice 265 Summary 266 Chapter 15 Putting It All Together 267 Examples of Cryptocurrency Crimes 268 Buying Illegal Goods 268 Selling Illegal Goods 268 Stealing Cryptocurrency 269 Money Laundering 269 Kidnap and Extortion 270 What Have You Learned? 270 Where Do You Go from Here? 273 Index 275.