ビットコインとイーサリアムの技術 / Bitcoin and Ethereum Technology

2018年10月3日(水)、ブロックチェーンハブ主催で開催されたブロックチェーンアカデミー「ビットコインとイーサリアムの技術」にて使用したスライドです。

Transcript

1. CSO / SFC ks91@blockchainhub.co.jp — — 2018-10-03 – p.1/66
2. ( ) SFC ( ) CSO (Chief Science Officer) 1993 ( ) 2006 ( ) SFC 18 P2P (Peer-to-Peer) 2011 SFC 2018 → ( ) — — 2018-10-03 – p.2/66
3. — — 2018-10-03 – p.3/66
4. Proof of Work SegWit — — 2018-10-03 – p.4/66
5. — — 2018-10-03 – p.5/66
6. (1) ( ) ⇒ P2P ⇒ ( ) — — 2018-10-03 – p.6/66
7. (2) (double spending) ( ) ⇒ ⇒ ( ) → ( ) ( ) ⇒ → → ⇒ → — — 2018-10-03 – p.7/66
8. / — — 2018-10-03 – p.8/66
9. / (1) 2,100 cm3 (cc) 1 1cm3 10 12.5cm3 ⇒ ⇒ ( ) — — 2018-10-03 – p.9/66
10. / (2) ( ) ( ) ( ) ( ) ( ) → ( ) — — 2018-10-03 – p.10/66
11. ∼ UTXO (= ) → — — 2018-10-03 – p.11/66
12. ∼ ท൪߸
    
    O ท൪߸
    
    O  ท൪߸
    
    O  લทͷμΠδΣετ λʔήοτҎԼͰͳ͍ͱ͍͚ͳ͍ ͸Έͩ͠ίʔφʔ μΠδΣετ͕λʔήοτҎԼʹͳΔΑ͏ʹೖΕΔద౰ͳ಺༰ ( ) → — — 2018-10-03 – p.12/66
13. ∼ ϖʔδ൪߸
    
    O ϖʔδ൪߸
    
    O  ϖʔδ൪߸
    
    O  ϖʔδ൪߸
    
    O  ϖʔδ൪߸
    
    O  ϖʔδ൪߸
    
    O  ϖʔδ൪߸
    
    O  ϖʔδ൪߸
    
    O  ͬͪ͜ͷྺ࢙͕༗ޮ ( ) — — 2018-10-03 – p.13/66
14. = (virtually) = = = : → ( ) — — 2018-10-03 – p.14/66
15. — — 2018-10-03 – p.15/66
16. — — 2018-10-03 – p.16/66
17. — — 2018-10-03 – p.17/66
18. 1. 10 ( ) 2. 3. 1 — — 2018-10-03 – p.18/66
19. /DLT ਖ਼౰ੑͷอূ ྫ
    
    6590
    ߏ଄ͱσδλϧॺ໊ ଘࡏੑͷূ໌ ྫ
    
    ࡞ۀূ໌෇͖ϋογϡνΣʔϯ །Ұੑͷ߹ҙ ྫ
    
    φΧϞτɾίϯηϯαε ϧʔϧͷهड़ ྫ
    
    #5$
    ͷҠస ɾ
    τϥϯβΫγϣϯͷ಺༰͕վ͟ΜͰ͖ͣɺ ɾ
    ͦͷΞηοτʹؔ͢ΔաڈͷτϥϯβΫγϣϯྻʹরΒͯ͠ໃ६͕ͳ͘ɺ ɾ
    ͔ͭɺਖ਼౰ͳϢʔβʹΑΓ౤ೖ͞Ε͍ͯΔ͜ͱΛอূ͢Δ ɾաڈʹ͋ͬͨτϥϯβΫγϣϯͷূڌΛຣফͰ͖ͣɺ ɾ
    ͔ͭɺաڈʹͳ͔ͬͨτϥϯβΫγϣϯͷূڌΛ፻଄Ͱ͖ͳ͍ ɾໃ६͢Δ;ͨͭͷτϥϯβΫγϣϯ͕౤ೖ͞Εͨ৔߹ɺ ɹ ͍ͣΕ
    ؔ༩͢Δશһ͕ಉ͡ยํΛબΜͰྺ࢙ͷதʹҐஔ͚ͮΔ ɾΞϓϦέʔγϣϯϩδοΫ
    Կ͕ਖ਼͍͠τϥϯβΫγϣϯ͔ΛܾΊΔ — — 2018-10-03 – p.19/66
20. - https://blockchain.info/ — — 2018-10-03 – p.20/66
21. 0 and/or “The Times 03/Jan/2009 Chancellor on brink of second bailout for banks” 2009 1 3 2 https://blockchain.info SEARCH 0 — — 2018-10-03 – p.21/66
22. (1) (= ) → — — 2018-10-03 – p.22/66
23. (2) M A 60BTC ( ) SegWit — — 2018-10-03 – p.23/66
24. SegWit (Segregated Witness; ) (witness) — — 2018-10-03 – p.24/66
25. SegWit (malleability) https://bitcoincore.org/en/2016/01/26/segwit-benefits/ — — 2018-10-03 – p.25/66
26. — — 2018-10-03 – p.26/66
27. Merkle ( ) Digest = SHA-256 × SHA-256 TX ( ) — — 2018-10-03 – p.27/66
28. Block Header Data Structure Field Description Size (bytes) Version 4 Digest Double SHA-256 value 32 Merkle root Double SHA-256 value 32 Time Seconds (since 1970-01-01T00:00 UTC) 4 Target Compressed format 4 Nonce Appropriate value 4 Merkle root is the digest of all TXs — — 2018-10-03 – p.28/66
29. OP_RETURN PUSH 0xaa21a9ed 4 (witness) SHA-256 32 Merkle — — 2018-10-03 – p.29/66
30. Proof of Work ( ) ( ) . . . : Hashcash (1997) SHA-1 20 ( ) 0 1 1 / — — 2018-10-03 – p.30/66
31. — — 2018-10-03 – p.31/66
32. CPU → GPU → FPGA → ASIC ( ) → → ( ) BTC — — 2018-10-03 – p.32/66
33. — — 2018-10-03 – p.33/66
34. POW ( ) Proof Of Work . . . — — 2018-10-03 – p.34/66
35. (2009 1 ∼2018 8 ) 2 → 2 2 → — — 2018-10-03 – p.35/66
36. https://bitcoin.org/en/developer-reference — — 2018-10-03 – p.36/66
37. 1 1 ∼ 2 — — 2018-10-03 – p.37/66
38. A-B — — 2018-10-03 – p.38/66
39. 2 2 ( ) Ripple Path — — 2018-10-03 – p.39/66
40. — — 2018-10-03 – p.40/66
41. (EVM) — — 2018-10-03 – p.41/66
42. (Ethereum) EVM (Ethereum Virtual Machine) — — 2018-10-03 – p.42/66
43. Vitalik Buterin, “Ethereum White Paper: A NEXT GENERATION SMART CONTRACT & DECENTRALIZED APPLICATION PLATFORM” 15 / — — 2018-10-03 – p.43/66
44. = run — — 2018-10-03 – p.44/66
45. Ether Ethereum EOA : Externally-Owned Account Ether EVM EVM — — 2018-10-03 – p.45/66
46. EVM : Ethereum Virtual Machine Gas — — 2018-10-03 – p.46/66
47. Frontier (2015) Homestead (2016) Metropolis Byzantium (2017) ← zkSNARKs ( ) → Zcash on Ethereum (ZoE) Constantinople (2018 ) Serenity — — 2018-10-03 – p.47/66
48. — — 2018-10-03 – p.48/66
49. ( ) ( ) ( vs. ) ( ) ( ) ( ) ⇒ ( : BBc-1) DLT : : — — 2018-10-03 – p.49/66
50. ( ) ⇒ (Casper) ( ) ⇒ ZoE (Zcash on Ethereum) ( vs. ) ( ) ⇒ Plasma ( ) ⇒ ( ) (Benevolent Dictator For Life (BDFL)) ( ) ⇒ — — 2018-10-03 – p.50/66
51. Proof of Work + Proof of Stake + — — 2018-10-03 – p.51/66
52. SHA-256 × SHA-256 SHA-256 × RIPEMD-160 (1 ) . . . scrypt ( ) Ethash (Dagger-Hashimoto ) DAG : Directed Acyclic Graph ( ) https://github.com/ethereum/wiki/wiki/Ethash — — 2018-10-03 – p.52/66
53. GHOST (Greedy Heaviest Observed Subtree) ⇒ GHOST ( ) “uncles” proof of work ( ) uncle uncles 7 GHOST — — 2018-10-03 – p.53/66
54. IUUQTFOXJLJQFEJBPSHXJLJ3BEJY@USFF key OK PATRICIA (Practical Algorithm To Retrieve Information Coded In Alphanumeric) Trie ( ) (key, value) RLP (recursive length prefix encoding) — — 2018-10-03 – p.54/66
55. Proof of Stake Casper — — 2018-10-03 – p.55/66
56. Proof of Stake ( ) ( ) — — 2018-10-03 – p.56/66
57. Proof of Stake ( ) H n (PD + id + t + . . .) ≤ 2n × balance d H n : n (ex. SHA-256 (n = 256)) PD : id : (ex. ) t : (ex. UNIX ( )) balance : d : (ex. ) PoW — — 2018-10-03 – p.57/66
58. Proof of Stake 3 1. 2. “Nothing at Stake” 3. 51% — — 2018-10-03 – p.58/66
59. : Proof of Stake Velocity Reddcoin — — 2018-10-03 – p.59/66
60. Nothing at Stake - = — — 2018-10-03 – p.60/66
61. Nothing at Stake - 100% Proof of Stake — — 2018-10-03 – p.61/66
62. 51% — — 2018-10-03 – p.62/66
63. Casper : Nothing at Stake (Slasher) 100 ⇒ — — 2018-10-03 – p.63/66
64. ( ) PoS — — 2018-10-03 – p.64/66
65. µRaiden Raiden Network Plasma — — 2018-10-03 – p.65/66
66. — — 2018-10-03 – p.66/66