パブリックチェーンとプライベートチェーン

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1. Blockchain Kyoto #16 ʮύϒϦοΫνΣʔϯͱϓϥΠϕʔτνΣʔϯʯ 2019/06/27 @גࣜձࣾϋ΢ευΡ

2. ੴ໺ ൏ޔʢIshino Shungoʣ ϑϦʔϥϯεWEBΤϯδχΞ ࣗݾ঺հ

3. ಺༰ ϏοτίΠϯͷ࿩ ύϒϦοΫνΣʔϯ ϓϥΠϕʔτνΣʔϯ

4. ατγɾφΧϞτ 2008೥ʹ҉߸ཧ࿦ʹؔ͢ΔϝʔϦϯάϦετʹ͋Δ ࿦จ͕౤ߘ͞Εͨɻ ʮBitcoin: A Peer-to-Peer Electronic Cash Systemʯ https://bitcoin.org/bitcoin.pdf

5. طଘͷΠϯλʔωοτΛհͨ͠ࢧ෷͍͸৴པͰ͖ ΔୈࡾऀػؔΛඞཁͱ͢Δɻ ୈࡾऀػؔΛඞཁͱ͠ͳ͍औҾΛߦ͏ͨΊʹɺ ৴པͰ͸ͳ͘҉߸ٕज़ʹجͮ͘γεςϜΛఏҊ͢Δɻ ατγɾφΧϞτ

6. ୈࡾऀػؔΛඞཁͱ͢ΔطଘγεςϜ

7. • 1ͭͷ୆ாσʔλΛ؅ཧ͢Δɻ • σʔλ͸ར༻ऀશһͰڞ༗͠ɺ୭Ͱ΋ӾཡͰ͖ ͯ୭Ͱ΋ॻ͖ࠐΊΔɻ • աڈͷཤྺ͸վ͟ΜͰ͖ͳ͍ɻ ཁ݅

8. • P2P • ϋογϡνΣʔϯ • Proof of Work ϏοτίΠϯ

9. P2PʢPeer to Peerʣ ◦ΫϥΠΞϯτɾαʔόʔ ◦P2P

10. ϋογϡνΣʔϯ σʔλ લϒϩοΫͷϋογϡ σʔλ લϒϩοΫͷϋογϡ σʔλ લϒϩοΫͷϋογϡ ϋογϡ ϋογϡ ϋογϡ

    ؔ਺ ؔ਺ ؔ਺

11. ϋογϡͱ͸ʁ ϋογϡ ؔ਺ “a” 0cc175b9c0f1b6a831c399e269772661 ??? b82228697f132b7a1e9dd60cf4641b1c “b” 92eb5ffee6ae2fec3ad71c777531578f 1GBͷจॻσʔλ

    b82228697f132b7a1e9dd60cf4641b1c • ೚ҙͷσʔλΛܾ·ͬͨ௕͞ͷ༧ଌͷͰ͖ͳ͍ จࣈྻʹม׵͢Δɻ • ϋογϡ͔Βݩͷσʔλ͸෮ݩͰ͖ͳ͍ɻ

12. ϋογϡνΣʔϯ ͸Δ͸͚͋΅ͷͳΜͱ ͔͔Μͱ͔ɻɻɻ 73d092da7cbaa68dc b 61c993f2163f248f46 a 8277e0910d750198 61c993f2163f248f465 73d092da7cbaa68dc

    1ecc7ce8854c2f2097 ؔ਺ ؔ਺ ؔ਺

13. ͸Δ͸͚͋΅ͷͳΜͱ ͔͔Μͱ͔ɻɻɻ 73d092da7cbaa68dc b 61c993f2163f248f46 a͸ؒҧ͍Ͱͨ͠ɻ 8277e0910d750198 07673603b3786cc1c 73d092da7cbaa68dc 1ecc7ce8854c2f2097

    ؔ਺ ؔ਺ ؔ਺ ˢϋογϡ͕มΘΔ ˣ⁋᧒͕߹Θͳ͘ͳΔ ˢվ᜵ ϋογϡνΣʔϯ

14. Proof of Work • ϋογϡؔ਺ͷॲཧ͸ҰॠͰऴΘΔͷͰɺશ෦ ܭࢉ͠௚ͤ͹OKͳঢ়ଶɻ • Proof of WorkͰͦΕΛ೉͘͢͠Δɻ

15. Proof of Work • ϒϩοΫʹσʔλͱؔ܎ͷͳ͍਺஋ʢφϯεʣ ΛՃ͑Δɻ • φϯεΛม͑ͳ͕ΒԿճ΋ϋογϡΛܭࢉ͠ɺ ܾ·ͬͨ஋ΑΓখ͞ͳϋογϡΛ୳͢ɻ •

    ͕͔͔࣌ؒΔΑ͏ʹͳΓɺվ᜵͕೉͘͠ͳΔɻ ϋογϡؔ਺ͷॲཧ͸ҰॠͰऴΘΔͷͰɺશ෦ܭࢉ͠ ௚ͤ͹վ᜵ͯ͠΋⁋᧒ͷ߹͏σʔλ͕؆୯ʹ࡞ΕΔɻ

16. ϋογϡνΣʔϯ φϯε σʔλ લϒϩοΫͷϋογϡ φϯε σʔλ લϒϩοΫͷϋογϡ φϯε σʔλ લϒϩοΫͷϋογϡ

    ϋογϡ ϋογϡ ϋογϡ ؔ਺ ؔ਺ ؔ਺

17. ύϒϦοΫνΣʔϯ • ϏοτίΠϯ͸ύϒϦοΫνΣʔϯ • ατγɾφΧϞτ͕ߟ͑ͨΑ͏ʹɺ୭Ͱ΋ωοτ ϫʔΫʹࢀՃͰ͖Δɻ • ωοτϫʔΫʹѱ͍ਓ͕͍ͯ΋جຊతʹ͸େৎ෉ɻ • ଞʹ΋EthereumͳͲଟ͘ͷϓϩδΣΫτ͕ύϒ

    ϦοΫνΣʔϯ

18. ύϒϦοΫνΣʔϯͷσϝϦοτ • ॲཧʹ͕͔͔࣌ؒΔɻ • νΣʔϯࣗମͷ࢓༷มߋ͕೉͍͠ɻ • σʔλ͸جຊશͯެ։ɻ • 51%߈ܸ

19. ϓϥΠϕʔτνΣʔϯ • ৴པͰ͖Δܾ·ͬͨਓ͚ͨͪͩ࢖͏ɻ • ॲཧ͕ߴ଎ • ࢓༷มߋ͕༰қ • νΣʔϯ؅ཧऀҎ֎͸σʔλΛݟΕͳ͍ •

    Ϗδωεʹ޲͍͍ͯΔɻ

20. ϓϥΠϕʔτνΣʔϯ • EthereumϓϥΠϕʔτωοτϫʔΫ • Hyperledger • Lisk, Cosmos, Polkadot

21. ·ͱΊ • ϏοτίΠϯ͸ύϒϦοΫνΣʔϯ • ύϒϦοΫνΣʔϯͱݺ͹ΕΔ΋ͷͱϓϥΠϕʔ τνΣʔϯͱݺ͹ΕΔ΋ͷ͕͋Δɻ • Ϗδωεʹ͸ϓϥΠϕʔτνΣʔϯ͕޲͍͍ͯ Δɻ •

    2ͭ͸ผ෺ͱࢥͬͯษڧͨ͠ํ͕ྑ͍ɻ