Cryptocurrencies Contents 1 SHA-256-based 1 1.1 Bitcoin ................................................. 1 1.1.1 Design ............................................. 1 1.1.2 History ............................................ 7 1.1.3 Economics .......................................... 9 1.1.4 Legal status and regulation .................................. 15 1.1.5 Criminal activity ....................................... 15 1.1.6 Security ............................................ 18 1.1.7 Alternative applications of the block chain .......................... 19 1.1.8 Data in the block chain .................................... 19 1.1.9 In academia .......................................... 19 1.1.10 In art, entertainment, and media ............................... 20 1.1.11 Bibliography ......................................... 20 1.1.12 See also ............................................ 21 1.1.13 Notes ............................................. 21 1.1.14 References .......................................... 22 1.1.15 External links ......................................... 36 1.2 Mastercoin ............................................... 36 1.2.1 References .......................................... 36 1.2.2 External links ......................................... 37 1.3 MazaCoin ............................................... 37 1.3.1 References .......................................... 37 1.3.2 External links ......................................... 38 1.4 Namecoin ............................................... 38 1.4.1 Records ............................................ 38 1.4.2 Uses ............................................. 38 1.4.3 History ............................................ 39 1.4.4 See also ............................................ 39 1.4.5 References .......................................... 39 1.4.6 External links ......................................... 40 1.5 NuBits ................................................. 41 1.5.1 Notes ............................................. 41 i ii CONTENTS 1.5.2 References .......................................... 41 1.5.3 External links ......................................... 41 1.6 Peercoin ................................................ 41 1.6.1 Transactions .......................................... 42 1.6.2 Creation of New Coins .................................... 42 1.6.3 Distinguishing features .................................... 42 1.6.4 Other ............................................. 43 1.6.5 See also ............................................ 43 1.6.6 References .......................................... 43 1.6.7 External links ......................................... 44 1.7 Titcoin ................................................. 44 1.7.1 History ............................................ 44 1.7.2 Specifications ......................................... 45 1.7.3 Awards and Recognition ................................... 45 1.7.4 Other adult cryptocurrencies ................................. 45 1.7.5 External links ......................................... 45 1.7.6 References .......................................... 45 2 Scrypt-based 47 2.1 Auroracoin .............................................. 47 2.1.1 History ............................................ 47 2.1.2 Controversy .......................................... 48 2.1.3 References .......................................... 48 2.1.4 External links ......................................... 49 2.2 Coinye ................................................. 49 2.2.1 Release ............................................ 49 2.2.2 Trademark infringement lawsuit ............................... 49 2.2.3 Developer departure and community takeover ........................ 49 2.2.4 Decline of use ......................................... 49 2.2.5 External links ......................................... 49 2.2.6 References .......................................... 50 2.3 Dogecoin ............................................... 51 2.3.1 Overview and history ..................................... 51 2.3.2 Fundraising .......................................... 52 2.3.3 Use and exchanges ...................................... 53 2.3.4 Transactions .......................................... 53 2.3.5 Mining parameters ...................................... 53 2.3.6 Block schedule ........................................ 54 2.3.7 Currency supply ........................................ 54 2.3.8 References .......................................... 54 2.3.9 External links ......................................... 57 2.4 Litecoin ................................................ 57 CONTENTS iii 2.4.1 History ............................................ 57 2.4.2 Development ......................................... 57 2.4.3 Differences from Bitcoin ................................... 58 2.4.4 Transactions ......................................... 58 2.4.5 Wallets ............................................ 58 2.4.6 Exchanges .......................................... 59 2.4.7 See also ............................................ 59 2.4.8 References .......................................... 59 2.4.9 External links ......................................... 59 2.5 PotCoin ................................................ 60 2.5.1 History ............................................ 60 2.5.2 Overview and specification .................................. 60 2.5.3 Usage ............................................. 60 2.5.4 Charitable fundraising .................................... 61 2.5.5 References .......................................... 62 3 CryptoNote-based 63 3.1 CryptoNote .............................................. 63 3.1.1 Origins ............................................ 63 3.1.2 Anonymous transactions and ring signatures ......................... 64 3.1.3 Double spending protection ................................. 64 3.1.4 Egalitarian proof of work .................................. 65 3.1.5 Adaptive network limits ................................... 65 3.1.6 Philosophy .......................................... 65 3.1.7 Current CryptoNote currencies ................................ 65 3.1.8 Controversy and criticism ................................... 69 3.1.9 See also ............................................ 70 3.1.10 References .......................................... 70 3.2 Monero (cryptocurrency) ....................................... 72 3.2.1 History ............................................ 72 3.2.2 Features ........................................... 73 3.2.3 Usage ............................................. 74 3.2.4 Limitations .......................................... 74 3.2.5 Ongoing work and side projects ................................ 74 3.2.6 Applications .......................................... 74 3.2.7 See also ............................................ 75 3.2.8 External links ......................................... 75 3.2.9 References .......................................... 75 4 Other proof-of-work 77 4.1 Dash (cryptocurrency) ......................................... 77 4.1.1 Overview ........................................... 77 iv CONTENTS 4.1.2 History ............................................ 78 4.1.3 References .......................................... 79 4.1.4 External links ......................................... 79 4.2 Primecoin ............................................... 79 4.2.1 Features ............................................ 80 4.2.2 Proof-of-work system ..................................... 80 4.2.3 See also ............................................ 80 4.2.4 References .......................................... 81 4.2.5 External links ......................................... 81 4.3 Ethereum ............................................... 81 4.3.1 Purpose ............................................ 82 4.3.2 Development ......................................... 82 4.3.3 Ether ............................................. 82 4.3.4 Contracts ........................................... 82 4.3.5 Implementations ....................................... 83 4.3.6 Media ............................................. 83 4.3.7 References .......................................... 83 4.3.8 External links ......................................... 84 5 Non proof-of-work 85 5.1 BlackCoin ............................................... 85 5.1.1 Proof-of-Stake ........................................ 85 5.1.2 Merchant adoption ...................................... 85 5.1.3 See also ............................................ 85 5.1.4 References .......................................... 85 5.1.5 External links ......................................... 86 5.2 Counterparty (technology) ....................................... 86 5.2.1 XCP .............................................. 86 5.2.2 Assets ............................................. 86 5.2.3 Decentralized Exchange (DEX) ............................... 89 5.2.4 Software ........................................... 89 5.2.5 Notable assets and issuers .................................. 90 5.2.6 Block Explorers ....................................... 91 5.2.7 References .......................................... 91 5.2.8 External links ......................................... 92 5.3 NEM (cryptocurrency) ........................................ 93 5.3.1 History ............................................ 93 5.3.2 Development ........................................