ビットコインの技術 / Bitcoin Technology

2021年8月25日(水)、ブロックチェーンハブ主催のブロックチェーンアカデミー「ビットコインの技術」にて使用したスライドです。

Transcript

1. Chief Science Officer / ks91@blockchainhub.co.jp — — 2021-08-25 – p.1/41
2. https://speakerdeck.com/ks91 — — 2021-08-25 – p.2/41
3. ( ) SFC ( ) CSO (Chief Science Officer) 1993 ( ) 2006 ( ) SFC 20 P2P (Peer-to-Peer) ( 2019 9 ) 2011 2018 2019 VR 2021.5 , VR 2021.7 , VR 2021.8 “PREFAB THE WORLDS”, VR 2021.8 “ALL THESE WORLDS ARE YOURS” ( ) → ( ) — — 2021-08-25 – p.3/41
4. : Kalle Rosenbaum , , — (2020) : 1 — — 2021-08-25 – p.4/41
5. Proof of Work SegWit — — 2021-08-25 – p.5/41
6. — — 2021-08-25 – p.6/41
7. (1) = ( ) ⇒ P2P ⇒ ( ) — — 2021-08-25 – p.7/41
8. (2) (double spending) ( ) ⇒ ⇒ ( ) → ( ) ( ) ( ) ⇒ → → ⇒ → — — 2021-08-25 – p.8/41
9. / — — 2021-08-25 – p.9/41
10. / (1) 2,100 cm3 (cc) 1 1cm3 10 6.25cm3 ⇒ ⇒ ( ) — — 2021-08-25 – p.10/41
11. / (2) ( ) ( ) ( ) ( ) ( ) ( ) → ( ) — — 2021-08-25 – p.11/41
12. ∼ UTXO (= ) → — — 2021-08-25 – p.12/41
13. ∼ ท൪߸
    
    O ท൪߸
    
    O  ท൪߸
    
    O  લทͷμΠδΣετ λʔήοτҎԼͰͳ͍ͱ͍͚ͳ͍ ͸Έͩ͠ίʔφʔ μΠδΣετ͕λʔήοτҎԼʹͳΔΑ͏ʹೖΕΔద౰ͳ಺༰ ( ) → — — 2021-08-25 – p.13/41
14. ∼ ϖʔδ൪߸
    
    O ϖʔδ൪߸
    
    O  ϖʔδ൪߸
    
    O  ϖʔδ൪߸
    
    O  ϖʔδ൪߸
    
    O  ϖʔδ൪߸
    
    O  ϖʔδ൪߸
    
    O  ϖʔδ൪߸
    
    O  ͬͪ͜ͷྺ࢙͕༗ޮ ( (= ) ) — — 2021-08-25 – p.14/41
15. = (virtually) = = = : → ( ) — — 2021-08-25 – p.15/41
16. — — 2021-08-25 – p.16/41
17. ϏοτίΠϯωοτϫʔΫ ɾ ճͷʮ࠾۷ʯྔ͸໿  ೥ຖʹ൒ݮ ɾ߹ܭ
    ໿   ສ #5$ ·Ͱ औҾͷొ࿥ ख਺ྉ ख਺ྉ औҾͷঝೝ ϚΠχϯά࣌ ϚΠχϯά ࠾۷ ͸ ֬཰తաఔ ฏۉ  ෼͓͖ʹ੒ޭ ૹۚࢦࣔ͸֤͕ࣗ΋ͭ ϓϥΠϕʔτΩʔͰ ແͨ͘͠Β࠶ൃߦෆՄ ϚΠφʔ ࠾۷ऀ ࢧ෷͍ɾ྆ସ ͳͲͷܦࡁ׆ಈ ར༻ऀ ϒϩοΫνΣʔϯ ݩா Πϯλʔωοτ্ͷԾ૝ωοτϫʔΫ ʜ ˞
    #5$
    
    ϏοτίΠϯͷ୯Ґ 
    #5$ ରԠ ϒϩοΫ ϒϩοΫ ϒϩοΫ औҾ ૹۚ औҾͷه࿥ ΞυϨε Ѽઌ ϓϥΠϕʔτΩʔ ຊਓͷূ໌ — — 2021-08-25 – p.17/41
18. — — 2021-08-25 – p.18/41
19. μΠδΣετ ϒϩοΫ O ϚΠχϯάใु ݻఆ஋
    ख਺ྉ
    ೖྗͷ߹ܭͱग़ྗͷ߹ܭͷࠩ .FSLMF
    ໦Λܭࢉͯ͠ ͦͷϧʔτ஋Λ֨ೲ ͍ͣΕऔҾه࿥͕औΓग़͞Εɺ ͦͷ࣌఺ͷਖ਼࢙ʹೖ͍ͬͯͳ͍΋ͷͳΒ ৽ͨͳϒϩοΫͷதʹ֨ೲ͞ΕΔ ᶃ
    ਖ਼౰ੑͷอূ ϏοτίΠϯͰ͸ 6590 ߏ଄ ᶄ
    ଘࡏੑͷূ໌ ϏοτίΠϯͰ͸࡞ۀূ໌෇͖ϋογϡνΣʔϯ ᶅ
    །Ұੑͷ߹ҙ ϏοτίΠϯͰ͸
    φΧϞτɾίϯηϯαε ϒϩοΫ O  ϒϩοΫ O  ϒϩοΫ O  ϒϩοΫ O  ϒϩοΫ O  ϒϩοΫ O  μΠδΣετ μΠδΣετ μΠδΣετ μΠδΣετ μΠδΣετ μΠδΣετ #5$ ੜ੒ औҾ औҾ औҾ औҾ ʜʜ ΑΓ௕͍ ࡞ۀূ໌ ͷίετ͕ΑΓ෷Θ Ε͍ͯΔ νΣʔϯ ͕༗ޮͱͳΔ μΠδΣετ
    㱡
    
    λʔήοτ 1SPPG
    0G
    8PSL ࡞ۀূ໌ աڈͷऔҾग़ྗ΁ͷࢀর σδλϧॺ໊ ެ։ݤ Ѽઌͱྔ ίΠϯ λʔήοτ ϊϯε ೖྗ ೖྗ ग़ྗ ग़ྗ 1. 10 ( ) 2. 3. 1 — — 2021-08-25 – p.19/41
20. /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 — — 2021-08-25 – p.20/41
21. - https://blockchain.com/ — — 2021-08-25 – p.21/41
22. 0 and/or “The Times 03/Jan/2009 Chancellor on brink of second bailout for banks” 2009 1 3 2 https://blockchain.com 0 BTC Block “Hex to ASCII Text Converter” — — 2021-08-25 – p.22/41
23. (1) (= ) → — — 2021-08-25 – p.23/41
24. (2) M A 60BTC ( ) SegWit — — 2021-08-25 – p.24/41
25. SegWit (Segregated Witness; ) (witness) ( ) ( TX ) — — 2021-08-25 – p.25/41
26. SegWit (malleability) https://bitcoincore.org/en/2016/01/26/segwit-benefits/ cf. Taproot ( ) — — 2021-08-25 – p.26/41
27. — — 2021-08-25 – p.27/41
28. Merkle ( ) Digest = SHA-256 × SHA-256 TX ( ) — — 2021-08-25 – p.28/41
29. 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 — — 2021-08-25 – p.29/41
30. OP_RETURN PUSH 0xaa21a9ed 4 (witness) SHA-256 32 Merkle — — 2021-08-25 – p.30/41
31. Proof of Work ( ) ( ) . . . : Hashcash (1997) SHA-1 20 ( ) 0 1 1 / — — 2021-08-25 – p.31/41
32. — — 2021-08-25 – p.32/41
33. CPU → GPU → FPGA → ASIC ( ) → → ( ) ⇒ BTC BTC — — 2021-08-25 – p.33/41
34. — — 2021-08-25 – p.34/41
35. POW ( ) Proof Of Work . . . — — 2021-08-25 – p.35/41
36. (2009 1 ∼2021 8 ) 2 → 2 2 → → — — 2021-08-25 – p.36/41
37. https://bitcoin.org/en/developer-reference — — 2021-08-25 – p.37/41
38. 1 1 ∼ 2 — — 2021-08-25 – p.38/41
39. A-B — — 2021-08-25 – p.39/41
40. 2 2 ( ) Ripple Path — — 2021-08-25 – p.40/41
41. — — 2021-08-25 – p.41/41