Bitcoin Contents 1 Overview 1 1.1 Bitcoin ................................................. 1 1.1.1 Etymology and orthography ................................. 1 1.1.2 Design ............................................ 1 1.1.3 History ............................................ 5 1.1.4 Economics .......................................... 6 1.1.5 Legal status and regulation .................................. 11 1.1.6 Criminal activity ....................................... 11 1.1.7 Security ............................................ 13 1.1.8 Data in the blockchain .................................... 14 1.1.9 In academia ......................................... 14 1.1.10 In art, entertainment, and media ............................... 14 1.1.11 See also ............................................ 14 1.1.12 Notes ............................................. 14 1.1.13 References .......................................... 15 1.2 History of Bitcoin ........................................... 26 1.2.1 Pre-history .......................................... 26 1.2.2 Creation ............................................ 26 1.2.3 Growth ............................................ 26 1.2.4 Prices and value history .................................... 27 1.2.5 Satoshi Nakamoto ....................................... 28 1.2.6 The fork of March 2013 ................................... 28 1.2.7 Regulatory issues ....................................... 29 1.2.8 Theft and exchange shutdowns ................................ 29 1.2.9 Taxation and regulation .................................... 30 1.2.10 Sports sponsorship ...................................... 31 1.2.11 References .......................................... 31 1.2.12 External Links ........................................ 35 1.3 Legality of bitcoin by country ..................................... 35 1.3.1 List by country ........................................ 35 1.3.2 Details by country ....................................... 35 1.3.3 Footnotes ........................................... 41 i ii CONTENTS 1.3.4 References .......................................... 42 2 People 47 2.1 Satoshi Nakamoto ........................................... 47 2.1.1 Development of bitcoin .................................... 47 2.1.2 Characteristics ........................................ 47 2.1.3 Candidates .......................................... 47 2.1.4 References .......................................... 49 2.1.5 External links ......................................... 51 2.2 Hal Finney ............................................... 51 2.2.1 Early life and education ................................... 51 2.2.2 Career ............................................ 51 2.2.3 Private life, illness ....................................... 51 2.2.4 Death ............................................. 51 2.2.5 References .......................................... 51 2.2.6 External links ......................................... 52 2.3 Gavin Andresen ............................................ 52 2.3.1 References .......................................... 52 2.3.2 External links ......................................... 52 2.4 Nick Szabo .............................................. 52 2.4.1 Bit gold ............................................ 53 2.4.2 Bitcoin speculation ...................................... 53 2.4.3 References .......................................... 53 2.4.4 External links ......................................... 54 2.5 Winklevoss twins ........................................... 54 2.5.1 Early life and education .................................... 54 2.5.2 ConnectU ........................................... 54 2.5.3 Bitcoin ............................................ 54 2.5.4 Popular culture ........................................ 55 2.5.5 References .......................................... 55 2.6 Mark Karpelès ............................................. 55 2.6.1 Early life and education .................................... 55 2.6.2 Career ............................................. 56 2.6.3 Arrest and prosecution .................................... 56 2.6.4 References .......................................... 56 2.6.5 External links ......................................... 57 3 Organizations 58 3.1 Bitcoin Foundation .......................................... 58 3.1.1 History ............................................ 58 3.1.2 Leadership .......................................... 58 3.1.3 Awards ............................................ 58 CONTENTS iii 3.1.4 Criticism ........................................... 58 3.1.5 References .......................................... 59 3.1.6 External links ......................................... 60 4 Technologies 61 4.1 Bitcoin network ............................................ 61 4.1.1 Transactions .......................................... 61 4.1.2 Mining ............................................ 61 4.1.3 Local system resources .................................... 62 4.1.4 Payment verification ..................................... 63 4.1.5 See also ............................................ 63 4.1.6 References .......................................... 63 4.2 Cryptocurrency ............................................ 63 4.2.1 Overview ........................................... 63 4.2.2 History ............................................ 64 4.2.3 Legality ............................................ 64 4.2.4 Timestamping ......................................... 66 4.2.5 Economics .......................................... 66 4.2.6 List .............................................. 67 4.2.7 Academic studies ....................................... 67 4.2.8 Criticism ........................................... 67 4.2.9 See also ............................................ 67 4.2.10 References .......................................... 68 4.2.11 Further reading ........................................ 70 4.2.12 External links ......................................... 70 4.3 Elliptic Curve Digital Signature Algorithm .............................. 70 4.3.1 Key and signature-size comparison to DSA .......................... 70 4.3.2 Signature generation algorithm ................................ 70 4.3.3 Signature verification algorithm ................................ 70 4.3.4 Correctness of the algorithm ................................. 71 4.3.5 Security ............................................ 71 4.3.6 See also ............................................ 71 4.3.7 Notes ............................................. 71 4.3.8 References .......................................... 72 4.3.9 External links ......................................... 72 4.4 Peer-to-peer .............................................. 72 4.4.1 Historical development .................................... 73 4.4.2 Architecture .......................................... 73 4.4.3 Applications .......................................... 76 4.4.4 Social implications ...................................... 77 4.4.5 Political implications ..................................... 77 4.4.6 Current research ....................................... 78 iv CONTENTS 4.4.7 See also ............................................ 78 4.4.8 References .......................................... 78 4.4.9 External links ......................................... 80 4.5 Proof-of-work system ......................................... 81 4.5.1 Background .......................................... 81 4.5.2 Variants ............................................ 81 4.5.3 List of proof-of-work functions ................................ 82 4.5.4 Reusable proof-of-work as e-money ............................. 82 4.5.5 Notes ............................................. 83 4.5.6 See also ............................................ 83 4.5.7 References .......................................... 83 4.5.8 External links ......................................... 83 4.6 SHA-2 ................................................. 84 4.6.1 Hash standard ......................................... 84 4.6.2 Applications .......................................... 85 4.6.3 Cryptoanalysis and validation ................................. 85 4.6.4 Test vectors .......................................... 86 4.6.5 Pseudocode .......................................... 86 4.6.6 Comparison of SHA functions ................................ 88 4.6.7 See also ............................................ 89 4.6.8 References .......................................... 89 4.6.9 External links ......................................... 90 5 Exchanges 91 5.1 ANX (Hong Kong company) ..................................... 91 5.1.1 Sub-brands .......................................... 91 5.1.2 History ............................................ 91 5.1.3 Company Growth ....................................... 91 5.1.4 Acquisitions .......................................... 92 5.1.5 Agreements .......................................... 92 5.1.6 References .......................................... 92 5.2 BitInstant ............................................... 93 5.2.1 History ............................................ 93 5.2.2 Criticism ........................................... 93 5.2.3 References .......................................... 93 5.2.4 External links ......................................... 94 5.3 Bitstamp ................................................ 94 5.3.1 Service