Blockchain Basic

Transcript

1. 1 #MPDLDIBJO
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2. 2 Quick Introduction ໊લɿ౉ล૑ଠ େֶɿܚጯٛक़େֶܦࡁֶ෦3೥ ৬ྺɿChronicled SoftBank Internship (6Χ݄ʣ NPO.ETIC Internship (3Χ݄ʣ ϩγΞΠϯλʔϯγοϓʢ1.5Χ݄ʣ ΠϯυӦۀ׆ಈ (1.5Χ݄ʣ ࠷ۙɿTwitterͱMediumʹྗΛೖΕ͍ͯ·͢ɻ Twitter (@souta__watanabe) ɹɹɹ ̍൪ڵຯ͋Δͷ͸ϒϩοΫνΣʔϯ͕ ɹɹɹ ࣾձʹ΋ͨΒ͢ΠϯύΫτΛϚΫϩతʹ ɹɹɹ ݟΔ͜ͱͰ͢ɻ
3. Chronicledͱ͸ʁ 3
4. Chronicledͱ͸ʁ 4
5. 5 Contents 1 ατγɾφΧϞτͱͦΕ͔Β Blockchainͱͦͷࢥ૝ 2 Ͳ͏ಈ͍͍ͯΔͷ͔ʁ Blockchainͷ࢓૊Έ 3 ੈؒͷظ଴஋ͱͷဃ཭ Blockchainͷ໰୊఺ 4 ৭ʑͳBlockchain Ϗδωεతͳࢹ఺ 5 ࠷ޙʹ ݸਓతͳࢥ૝ͱ࣮ݱ͍ͨࣾ͠ձ P7 P54 P21 P81 P92
6. 6 ࠓճ͸ಛʹஅΓແ͘ʮϒϩοΫνΣʔϯʯ ͱݴ͏࣌ɺ ϏοτίΠϯϒϩοΫνΣʔϯΛࢦ͠·͢ɻ
7. 1 Blockchain ͱͦͷࢥ૝
8. 8 “The technology most likely to change the next decade of business is not the social web, big data, the cloud, robotics, or even artificial intelligence. It’s the blockchain, the technology behind digital currencies like Bitcoin.” )BSWBSE
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   “The progress of mankind is marked by the rise of new technologies and the human ingenuity they unlock. In distributed ledger technology, we may be witnessing one of those potential explosions of creative potential that catalyse exceptional levels of innovation. The technology could prove to have the capacity to deliver a new kind of trust to a wide range of services. As we have seen open data revolutionise the citizen’s relationship with the state, so may the visibility in these technologies reform our financial markets, supply chains, consumer and business-to-business services, and publicly-held registers.”
   
   
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   Blockchain΁ͷظ଴
9. 9 ੈؒͷظ଴ͱ࣮ࡍʹͰ͖Δ͜ͱʹ͸େ͖ͳΪϟοϓ͕͋Γ·͢ɻ ͱΓ͋͑ͣϒϩοΫνΣʔϯɻϒϩοΫνΣʔϯͳΒͳΜͰ΋Ͱ͖Δ ͱ͍͏ͷ͸ӕͩͱࢥ͍·͢ɻʮͦΕɺϒϩοΫνΣʔϯ࢖ͬͨΒٯʹ ޮ཰ѱ͘ͳΔΑͶʁʯΈ͍ͨͳϓϩδΣΫτ͸୔ࢁ͋Γ·͢ɻ ʢP93Ͱ΋৮Ε·͢ɻʣ ࠓޙɺϒϩοΫνΣʔϯͰͰ͖Δ͜ͱͰ͖ͳ͍͜ͱ͕ݦࡏԽͯ͘͠Δ ʹͭΕͯҰճ೤΋ྫྷΊͯ͘Δͱࢥ͍·͢ɻʢ.comόϒϧΈ͍ͨͳʣ ྲྀߦʹ࿭Θ͞Εͣʹٕज़ͷਐԽ͔ΒͰ͖Δ͜ͱΛ͔ͬ͠ΓݟۃΊ͍ͯ͘ ͷ͕ඇৗʹେࣄͩͱߟ͍͑ͯ·͢ɻ ݸਓతͳελϯεᶃ
10. 10 ݸਓతͳελϯεᶃ ϒϩοΫνΣʔϯ͸ૣ͗͢·Ͱ͸͠ͳ͍͚Ͳɺ·ͩૣ͍ɻ ϒϩοΫνΣʔϯͦΕࣗମͱɺαʔϏε͸ผ࣍ݩͰߟ͑Δ ඞཁ͕͋ΔɻFacebookΛ࢖͏࣌ʹͩΕ΋ɺ͜Εʹ͸Hadoop ͕࢖ΘΕ͍ͯΔͳɺεήʔʂͱ͸ͳΒͳ͍͠ɺGoogleΛ࢖ͬͯ ͍ͯ୭΋HTMLεήʔͱ͸ͳΒͳ͍ɻ ٕज़తͳͱ͜Ζʹ஫໨͕ू·͍ͬͯΔ಺͸ૣ͍ؾ͕͠·͢ɻ
11. ࢥ૝ 11 ੈͷதΛ෼ࢄԽʢ୤தԝूݖԽʣ͢Δɻ
12. 12 ͱݴΘΕΔ͕ɺ ͦΕ͸ޙ෇ͨ͠΋ͷͰ ατγɾφΧϞτ͸໌จԽ͍ͯ͠·ͤΜɻ ͔͠͠ɺɺɺ
13. 13 Genesis Blockͷҙຯ https://blockchain.info/ 04ffff001d0104455468652054696d65732030332f4a616e2f323030392043 68616e63656c6c6f72206f6e206272696e6b206f66207365636f6e6420626 1696c6f757420666f722062616e6b73 (σίʔυࡁΈ) �� EThe Times 03/Jan/2009 Chancellor on brink of second bailout for banks “Chancellor on brink of second bailout for banks” ࡒ຿େਉ2౓໨ͷۜߦٹࡁ͔ʁ ͱ͍͏จࣈ͕ຒΊࠐ·Ε͍ͯΔɻ
14. 14 27 transaction 24 block 20 transactions 17 nodes 17 attacker 16 chain 15 blocks 14 network 14 honest 14 Hash 13 Block 11 proof-of-work 10 probability 9 timestamp 9 system 9 Owner 9 CPU 8 trusted 8 only 8 next 7 proof 7 majority 7 coins 7 chain, 7 Prev 7 Nonce 7 Merkle 6 working 6 work6 6 value 6 time 6 sender 6 number 6 node 6 make 6 long 6 double 6 block, 6 Nodes 6 Key 6.trust # Word 47 times transaction(s) 30 times block(,) 28times honest + trust(ed) 23 times chain(,) 23 times node(,) 5IJT
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    14 ϓϩάϥϛϯάݴޠPythonΛ༻͍࿦จΛ෼ੳ͠·ͨ͠ɻ෼ੳͷ݁Ռɺ࿦จதʹʮtrustʯͱʮtransactionʯ͕ଟ༻͞Ε͍ͯΔͱ͍͏݁ՌΛಘ·ͨ͠ɻ # Word ατγɾφΧϞτͷ࿦จ෼ੳ
15. 15 • bitcoinͷ্ݶ͸20,999,999ສຕɻҰൠతʹ͸2100ສຕͱݴΘΕΔɻ • 2140೥ʹ࠾۷ऴྃɻ • 4೥ʹ1౓൒ݮظ͕͋Δɻ bitcoin͸ҙਤతʹΠϯϑϨʹͳΒͳ͍Α͏ʹઃܭ͞Ε͍ͯΔɻ →௨՟͕঎඼ʹର͠ऑ͘ͳΒͳ͍Α͏ʹઃܭ͍ͯ͠Δɻ Bitcoinͷઃܭ
16. 16 Bitoin͕ղ͖͔ͨͬͨ໰͍ʢԾઆʣ A peer to peer version of electronic cash would allow online payments to be sent directly from one party to another without going through a financial institution. ࣗ෼ͷ͓ۚΛ୭ʹ΋ࢭΊΒΕΔ͜ͱແࣗ͘෼ͷ޷͖ͳλΠϛϯάͰ ૹۚ͢Δʹ͸Ͳ͏͢Ε͹Α͍͔ʁ
17. 17 ࠃՈ΍ۜߦͳͲͷதԝूݖػؔ΁ͷෆຬ͕͋ͬͨͷͰ͸ͳ͍͔ʁ ͱݴΘΕΔ͜ͱ͕ଟ͍Ͱ͢ɻ
18. 18 By ConsenSys
19. 19 ᶃվ͟Μ͕ۃΊͯࠔ೉Ͱ͋Δɻ ᶄ࣮࣭θϩɾμ΢ϯλΠϜͳγεςϜɻ ᶅ҆ՁʹߏஙՄೳɻ ᶃʹؔͯ͠͸ͳͥվ͟Μ͕ࠔ೉͔ͱ͍͏ͱ2ͭͷಛ௃͕͋Δɻ ̍ͭ໨͸ʮ෼ࢄతʯͳ؅ཧγεςϜ͔ͩΒɻ ͜ͷΑ͏ͳγεςϜΛҰൠతʹP2Pͱ͍͏ɻʢPeer to Peer) ैདྷɺ͓ۚͷऔҾ͸ۜߦͳͲͷୈ̏ऀػ͕ؔ஥հ͢Δ͜ͱʹ Αͬͯ৴པੑΛ୲อ͖͕ͯͨ͠ɺ ϒϩοΫνΣʔϯͰ͸શͯͷ ཤྺΛօͰڞ༗͢Δ͜ͱʹΑͬͯ৴པੑΛ୲อ͍ͯ͠Δɻ ͜ΕʹΑͬͯୈ̏ऀػ͕ؔඞཁͳ͘ͳΔͱҰൠతʹݴΘΕ͍ͯΔɻ ̎ͭ໨͸ʮ֤औҾཤྺ͸ॱ൪ʹϒϩοΫʹऩೲ͞Ε͍֤ͯͯϒϩο Ϋ͕௚લͷϒϩοΫͱͭͳ͕͍ͬͯΔͨΊʹվ͟Μ͕ࠔ೉ʯ ྫ͑͹ɺσʔλ͕อ؅͞Ε͍ͯΔ̍ͭͷϒϩοΫͷσʔλΛվ͟Μ ͢ΔͱɺνΣʔϯͰܨ͕͍ͬͯΔલɺޙΖͷσʔλͱͷ੔߹ੑ͕औΕ ͳ͘ͳΔͷͰվ͟ΜΛͨ͠Βॠ࣌ʹݟ͔ͭΔɻ ϒϩοΫνΣʔϯͷಛ௃ ֵ৽ੑ ܦࡁ׆ಈͷج൫͸औҾͩͬͨɻྺ࢙తʹ͍··ͰऔҾ૬खͷ৴པੑ ͷ୲อͷҝʹඇৗʹଟ͘ͷίετ͕͔͔͖ͬͯͨɻ ৴པੑ୲อͷ࢓૊Έͷྫ ɾ֨෇͚ɺձܭ؂ࠪ ɹɾެূਓ ɹɾొه ɹɾதԝۜߦ ͔͠͠ɺϒϩοΫνΣʔϯΛར༻͢Δ͜ͱͰࢀՃऀಉ͕࢜ ૬ޓʹڠྗɾ؂ࢹ͢ΔγεςϜ͕੒ΓཱͭͷͰ ࣾձγεςϜΛҡ࣋͢ΔҝʹଟେͳίετΛ෷ͬͯ ߏங͖ͯͨ͠தԝूݖతͳୈ3ऀػ͕ؔෆཁʹͳΔɻ ϒϩοΫνΣʔϯͱ͸ʁ
20. 20 3छྨͷϒϩοΫνΣʔϯ ύϒϦοΫ ίϯιʔγΞϜ ϓϥΠϕʔτ ϚΠχϯάϊʔυ ੍ݶͳ͠ ੍ݶՄೳ ੍ݶՄೳ ϒϩοΫνΣʔϯӾཡ Φʔϓϯ ੍ݶՄೳ ੍ݶՄೳ ϒϩοΫੜ੒ PoW΍PoSͳͲͷ೉қ ౓ͷߴ͍࢓૊Έ͕ඞཁ ೚ҙʢϒϩοΫੜ੒ओମ Λݶఆͤ͞Δ৔߹͕ଟ ͍ʣ ೚ҙ ϚΠχϯάใु ඞਢ ೚ҙ ೚ҙ Ϣʔεέʔε Bitcoin, EthereumͳͲ αϓϥΠνΣʔϯͳͲ اۀ಺σʔλ؅ཧͳͲ ͜ͷ3ͭͷ෼͚ํʹ͸ॾઆ͋ΔͷͰɺ஫ҙ͕ඞཁɻ
21. Blockchainͷ ࢓૊Έ
22. 22 BitcoinͷϝϯλϧϞσϧ Source :ܚጯٛक़େֶSFC ࡈ౻ઌੜͷSFCެ։तۀࢿྉΑΓഈआ bitcoinͷ૯ྔ 1 satoshi ϚΠχϯάͷ࿩
23. 23 P23Λࢀর P2PωοτϫʔΫ ϋογϡؔ਺ɾిࢠॺ໊ PoWɺPoSɺPoIɺPoE ͳͲ͋Γ·͢ɻ ίϯηϯαεΞϧΰϦζϜ ΠʔαϦΞϜʹݶΔɻΠʔα ϦΞϜͷͱ͜ΖͰޙड़ɻ εϚʔτίϯτϥΫτ ϒϩοΫνΣʔϯͷॏཁͳߏ੒ٕज़
24. 24 P2PωοτϫʔΫ Source : ܦࡁ࢈ۀল ίϯϐϡʔλʔಉ͕࢜ಉ͡໨తͰ઀ଓ͠ɺωοτϫʔΫΛܗ੒͢Δɻ ϊʔυ͕ಉ͡ॲཧΛ͢Δ͜ͱ͕Ͱ͖ΔͷͰɺ1ͭͷϊʔυ͕ఀࢭͯ͠΋γεςϜશମʹӨڹ͠ͳ͍ͷ͕ಛ௃ɻ
25. 25 ʮϒϩοΫʯͱʮνΣʔϯʯ ໊લͷ௨ΓɺʮϒϩοΫʯͱʮνΣʔϯʯͰߏ੒͞Ε͍ͯΔɻ
26. 26 Former block’s hash value Former block’s hash value Former block’s hash value Nonce Nonce Nonce Transaction Transaction Transaction Transaction Transaction Transaction Transaction Transaction Transaction Transaction Transaction Transaction •  A block is including transactions in a certain period of time. •  A block is including the former block’s hash value. Therefore, it looks like a chain structure. •  The hash is recomputed for each value until a hash containing the required number of zero bits is found. (set by “the difficulty”) The Structure of Blocks
27. 27 ϒϩοΫͷߏ଄ લͷϒϩοΫͷϋογϡ஋ ϊϯε TX ݫີʹΈΔͱ΋ͬͱ৭ʑೖ͍ͬͯΔɻ τϥϯβΫγϣϯͷϚʔΫϧ໦ͷϧʔτϋογϡ λΠϜελϯϓ λʔήοτ TX TX TX TX TX TX TX TX TX TX TX TX TX TX TX TX TX TX
28. 28 ϒϩοΫͷߏ଄ ϒϩοΫϔομʔ͸80όΠτͰ͋ΔҰํͰɺ̍ͭͷτϥϯβΫγϣϯͷσʔλྔ͸250όΠτ͋Δɻ Source :mastering Bitcoin
29. 29 ϒϩοΫͷߏ଄ ϒϩοΫϔομʔ લͷϒϩοΫͷϋογϡ஋ ਖ਼֬Ͱ͸ͳ͍ Source :mastering Bitcoin
30. 30 ϒϩοΫͷߏ଄ Merkle treeͷrootͱ͸ʁ τϥϯβΫγϣϯͱͱͳΓͷτϥϯβΫγϣϯΛ͋Θͤͨ΋ͷΛϋογϡԽ͠·͢ɻ TxaͱTXbΛϋογϡԽ͠ɺHaͱHbΛ࡞ΓɺHaͱHbΛϋογϡԽ͢Δ͜ͱʹΑͬͯHabΛ࡞Γ·͢ɻ Ha͕վ͟Μ͞ΕΔͱ͜ͷ৔߹ɺMerkle rootͷ஋͕มΘΓ·͢ɻ
31. 31 ϒϩοΫͷߏ଄ Former block’s hash value Nonce Transaction Transaction Transaction Transaction 1MόΠτͷϒϩοΫʹ4000݅ఔ౓ͷ औҾΛ࣮ݱͰ͖Δɻ ϒϩοΫͷੜ੒ใु͕12.5BTCʢ1200ສԁʣ ͱ͢Δͱɺ1݅͋ͨΓͷऔҾʹ3,000ԁ ͔͔͍ͬͯΔ͜ͱʹͳΔɻ ʢߴ͍Ͱ͢ΑͶwʁʣ ແ͔Βੜ͡Δ௨՟ൃߦӹͰิర͍ͯ͠Δɻ
32. 32 ϒϩοΫͷߏ଄ ॲཧ͖͠Εͳ͔ͬͨτϥϯβΫγϣϯ͸ ະॲཧऔҾͱͯ͠ཷ·͍ͬͯ͘ɻ ϏοτίΠϯͷऔҾੑೳ͸1ඵؒʹ7औҾ ΫϨδοτΧʔυܾࡁͩͱ1ඵؒʹ2000݅ ϏοτίΠϯ͸ܾࡁ׬ྃੑͱ͍͏఺Ͱ ༏Ε͍ͯͳ͍ɻSegwitͳͲͷղܾࡦ ͸໛ࡧதɻ ͨͩ͠ɺϓϥΠϕʔτνΣʔϯͰ͋Ε͹ɺ ඵؒ3000ʙ4000͍͚ͨΓ΋͢Δɻ 2018/02/10
33. 33 Former block’s hash value Former block’s hash value Nonce Nonce Transaction Transaction Transaction Transaction Transaction Transaction Transaction Transaction νΣʔϯͷͭͳ͗ํ SHA256ͱ͍͏ϋογϡؔ਺Λ༻͍͍ͯΔɻ ౉ล૑ଠ 010100001001010010010110………… 256ܻͷ0 or 1 SHA256 ౉ล૑ଠ 010100001001010010010110………. 256ܻͷ0 or 1 1111010100100100100111000………. 256ܻͷ0 or 1 ಉ͡஋ ☓ ෆՄٯ ࣮ࡍʹ͸μϒϧϋογϡ ͕࢖ΘΕΔɻ
34. 34 ☓ ☓ ˎReference : Nonce 34 •  The nonce in a Bitcoin is a 32bit (4byte). •  In terms of Bitcoin, the difficulty of finding “nonce” is set. It is about 10 minutes. Hash Hash Hash Nonce : A Nance : C Nance : B Other data : bbbbbbbbbbbb Other data : bbbbbbbbbbbb Other data : bbbbbbbbbbbb 21333508fdw9cujsighwehɾɾɾ 000000000000000012ec2h93ɾɾ 0000012dwvf344brthhh64ɾɾɾ 10 min
35. 35 ϋογϡ஋ 35 01010100101011110111010000010111111………… 0 or 1ͷ256ܻ 16ਐ๏ͷ64ܻ (͜Ε͸ϒϩοΫ#1000000ͷϋογϡ஋) 000000000003ba27aa200b1cecaad478d2b00432346c3f1f3986da1afd33e506 ͜ͷ0ͷ਺Λ “difficulty” ͱݴ͏ɻ ௚ײతʹ෼͔Δ͕ɺઌ಄͔Β࿈ଓ͢Δ0ͷ਺͕ଟ͘ͳΕ͹ͳΔ΄Ͳ ৚݅Λຬͨ͢஋Λݟ͚ͭΔͷ͕೉͘͠ͳΔɻ ฏۉ10෼Ͱݟ͔ͭΔΑ͏ʹࣗಈௐ੔͞ΕΔɻͳͷͰɺϚΠχϯάύϫʔ ͕େ͖͘ͳΕ͹ͳΔ΄Ͳdifficulty΋ߴ͘ͳΔɻ #1000000ͷϒϩοΫɻ0͕11ݸɻ #100ͷϒϩοΫɻ0͕8ݸɻ #500000ͷϒϩοΫɻ0͕18ݸɻ ౰࣌͸ଟ෼0͕9 or 10ݸҎ্Ͱ͋Ε͹ΦοέΠɻ
36. 36 ʲ+αʳϋογϡ஋Λ୳ٻͯ͠ΈΔ 36 1. ଱িಥੑ X Y H(X) = H(Y) ୭΋ɹX != Y ͔ͭ H(X) = H(Y)ͱͳΔΑ͏ͳ XͱYͷ૊Έ߹ΘͤΛݟ͚ͭΔ͜ͱ͕Ͱ͖ͳ͍ɻ ͜͜Ͱॏཁͳͷ͸ɺXͱYͷ૊Έ߹Θ͕ͤʮଘࡏ͠ͳ͍ʯ Ͱ͸ͳ͘ɺʮ୭΋ݟ͚ͭΔ͜ͱ͕Ͱ͖ͳ͍ʯͱ͍ͯ͠Δ఺ Possible Inputs Possible outputs Πϯϓοτ૯ྔ͕Ξ΢τϓοτ૯ྔΑΓ΋େ͖͍ ͨΊিಥ͸ଘࡏ͢Δɻ
37. 37 ʲ+αʳϋογϡ஋Λ୳ٻͯ͠ΈΔ 37 1. ଱িಥੑ ͍͔ʹͯ͠ݟ͚ͭΔ͔ʁ 2ͷ130৐෼ͷΠϯϓοτΛ༻ҙ͢Δɻͦͷ৔߹ɺ99.8%ͷཱ֬Ͱিಥ͕ݟ͔ͭΔɻ Ͱ΋͜Ε͚ͩͷΠϯϓοτΛࢼ͢ʹ͸࣮ࡍ͕͔͔࣌ؒΓ͗ͯ͢ແཧͩΑͶɻ ೚ҙͷਓ਺͕ೖ͍ͬͯΔ෦԰Ͱࣗ෼ͱಉ͡஀ੜ೔ͷਓΛݟ͚ͭΔͷ͸೉͍͕͠ɺ ಉ͡஀ੜ೔ͷ2ਓΛ୳͢ͷ͸ൺֱత؆୯ͳͷͱҰॹɻ ͪͳΈʹɺিಥ͕ͳ͍ϋογϡؔ਺͸ݟ͔͍ͭͬͯͳ͍ɻ
38. 38 ʲ+αʳϋογϡ஋Λ୳ٻͯ͠ΈΔ 38 1. ଱িಥੑ ࣮ࡍʹSHA-1͸িಥ͕ݟ͔ͭͬͨɻʢ҆શͰͳ͍ͱূ໌͞Εͨʣ
39. 39 ిࢠॺ໊ͷϓϩηε ૹ৴ऀ ड৴ऀ ࢀߟɿϒϩοΫνΣʔϯͷ࢓૊Έͱཧ࿦ ᶃΩʔϖΞͷ࡞੒ ૹ৴ऀͷൿີ伴 ૹ৴ऀͷެ։伴 ૹ৴ऀͷެ։伴 ᶄެ։伴ͷૹ෇ ᶅిࢠॺ໊ͷ࡞੒ ిࢠσʔλʢݪຊʣ ిࢠॺ໊ ݪຊ→ిࢠॺ໊͸ૹ৴ऀͷ ൿີ伴Λݩʹ࡞੒͞ΕΔɻ ᶆిࢠσʔλͱిࢠॺ໊ͷૹ෇ ిࢠσʔλʢݪຊʣ ిࢠॺ໊ ᶇిࢠॺ໊ͷ෮߸Խ ిࢠσʔλʢ෮߸݁Ռʣ ᶈൺֱ ϒϩοΫνΣʔϯͰ͸֤τϥϯβΫγϣϯʹ1ͭͣͭిࢠॺ໊ͱެ։伴͕෇༩͞Ε͍ͯΔɻ
40. 40 ʲ+αʳൿີ伴ͱެ։伴 ൿີ伴͸ϥϯμϜͳ਺஋ʹΑͬͯߏ੒͞ΕΔɻެ։伴͸ൿີ伴Λପԁۂઢ ൿີ伴͕όϨΔͱࢿ࢈Λ؆୯ʹ౪ΊΔঢ়ଶʹͳΔɻൿີ伴ͷ෮ݩ΋ෆՄೳɻ Ұൠతʹ͸ɺऔҾॴ͕ൿີ伴ͷ؅ཧΛ͍ͯ͠ΔɻࠓճͷίΠϯνΣοΫͷҰ݅͸ ίΠϯνΣοΫ͕ൿີ伴Λϗοτ΢ΥϨοτͰ؅ཧ͓ͯ͠ΓϋοΩϯά͞Εͨɻ ൿີ伴ͷྫɿ Source : mastering bitcoin
41. 41 ʲ+αʳൿີ伴ͱެ։伴 Source : mastering bitcoin ൿີ伴͸ɺ16ਐ๏ͷ64ܻͱͳ͍ͬͯΔɻ16ͷ64৐Ͱ2ͷ256৐ͱಉ͡਺ɻ 2ͷ256৐ͬͯͲΕ͘Β͍ʁ →2ͷ256৐ ≒ 10ͷ77৐ ≒ 10ͷ80৐ ≒ ؍ଌՄೳͳӉ஦ͷݪࢠͷ਺ ͱΓ్͋͑ͣํ΋ͳ͘େ͖͍਺Ͱ͢ স
42. 42 ʲ+αʳൿີ伴ͱެ։伴 Source : mastering bitcoin ପԁۂઢ ެ։伴͸ൿີ伴ͷପԁۂઢ্ͷεΧϥʔഒࢉΛ༻͍ͯ ࡞੒͞ΕΔɻͦͷࣄʹΑͬͯެ։伴͔Βൿີ伴ͷ࡞੒ ͸ࣄ্࣮ෆՄೳʹͳ͍ͬͯΔɻ ͜͜͸๻΋෼͔͍ͬͯͳ͍ͷͰڭ͍͑ͯͩ͘͞ɻ
43. 43 ʲ+αʳΞυϨε Source : mastering bitcoin BitcoinΞυϨε͸1͔Β࢝·Δɻ਺ࣈͱจࣈͰද͞ΕΔɻ ΞυϨε͸ެ։伴ΛSHA256Ͱϋογϡͯ͠ɺ͞ΒʹɺRIPEMD60Ͱ҉߸Խ͍ͯ͠Δɻ ΞυϨε͔Βެ։伴ͷ࡞੒͸ෆՄೳɻ
44. 44 ৭ʑͳίϯηϯαεΞϧΰϦζϜ PoW (Proof of Work) PoS (Proof of Stake) PoI (Proof of Importance) PBFT ατγφΧϞτʹΑΓߟҊ͞ΕΔɻ ϏοτίΠϯϒϩοΫνΣʔϯͰ࠾༻͞Ε͍ͯΔɻ ϚΠχϯάʹΑΔܭࢉྔʹΑΔূ໌͕͞Ε͍ͯΔɻ 51%໰୊ɺϑΝΠͳΓςΟʔ໰୊ɺੑೳݶքɺ ϒϩοΫͷ༰ྔͳͲͷ໰୊఺Λ๊͍͑ͯΔɻ ΠʔαϦΞϜϒϩοΫνΣʔϯʹಋೖ༧ఆ ʢ2018/02/13ݱࡏʣɻ௨՟ͷอ༗ྔʹΑͬͯϒϩο Ϋ࡞੒ऀͷ༏ઌ౓͕ҟͳΔɻݫີʹ͍͏ͱɺอ༗௨ ՟ྔʹैͬͯϋογϡͷܭࢉ೉қ౓͕มΘΔɻ PoWΑΓ΋ిྗফඅ͕গͳ͘ͳΔͷ͕ྑ͍ॴɻ HyperLedger FablicͰ࠾༻͞Ε͍ͯΔɻϑΝΠφϦ ςΟʔͷෆ࣮֬ੑΛղফ͍ͯ͠ΔɻࢀՃऀͷҰਓ͕ ࣗ෼ΛؚΉશࢀՃऀʹཁٻΛૹΓɺͦͷཁٻͷղ౴ ݁Ռ͔Βଟ਺ܾʹΑͬͯϒϩοΫΛ֬ఆͤ͞Δɻ ίϯιʔγΞϜ޲͚ɻϊʔυ͕εέʔϧ͠ͳ͍ɻ NEMͰ࠾༻͞Ε͍ͯΔɻ௨՟อ༗ྔ͚ͩͰ͸ͳ͘ औҾྔͱऔҾͨ͠ਓ΋౿·͑ͯใु͕༩͑ΒΕΔ ࢓૊ΈɻωϜͷωοτϫʔΫΛ࢖͏ਓʹݖݶ͕ ༩͑ΒΕΔ࢓૊Έɻ
45. 45 PoW (Workflow Systemᶃ) Participants : A, B, C, D, E, F, G Miners : α, β, γ, δ, ε A B C D E F α β γ ε δ Blockchain
46. 46 PoW (Workflow Systemᶄ) A send 10BTC to C, C send 5BTC to F, E send 8BTC to D A→C, C→F, E→ D A B C D E F α β γ ε δ
47. 47 PoW (Workflow Systemᶅ) A B C D E F α β γ ε δ The transactions are broadcasted to participants and miners at the same time. Transactions like A→C, C→F, E→D are also the same.
48. 48 PoW (Workflow Systemᶆ) A B C D E F α β γ ε δ The miners which received transactions confirm signatures and start to find Nance.
49. 49 PoW (Workflow Systemᶇ) A B C D E F α β γ ε δ The one who finds Nonce will make a new block and broadcast it to all participants and miners.
50. 50 PoW (Workflow Systemᶈ) A B C D E F α β γ ε δ Miners which received the block confirm it and add it to own blocks.
51. 51 τϥϯβΫγϣϯͷ࢓૊Έ Source : mastering bitcoin Alice͕Bobʹ0.0150BTCૹۚ͢ΔࡍʹɺTo Bob : 0.0150ɺTo Alice : 0.0845BTC Λૹ͍ۚͯ͠ΔɻAlice to Alice΋ϒϩοΫνΣʔϯ্ʹهࡌ͞ΕΔɻ ΞυϨε͕Ұॹ
52. 52 ʲ+αʳτϥϯβΫγϣϯ Source : mastering bitcoin τϥϯβΫγϣϯͷߏ଄ Lightning NetworkͳͲͰ࢖ΘΕΔɻ
53. 53 ʲ+αʳτϥϯβΫγϣϯ Source : mastering bitcoin ϏοτίΠϯΛ࢖͏ʹ͋ͨͬͯͷ৚݅Λఆٛͨ͠΋ͷ͕Locking script Πϯϓοτ Ξ΢τϓοτ ʴ ిࢠॺ໊
54. Blockchainͷ ໰୊఺
55. 55 ݱ࣌఺Ͱͷ Blockchainͷ ໰୊఺ͱղܾࡦ 1 ϑΝΠφϦςΟʔ ࣮࣌ؒੑ 2 ZK-SNARKS͸͋Δ͚Ͳ ൿಗੑ 3 Segwit ͱ Segwit2X εέʔϥϏϦςΟʔ 4 ͦͷଞ 5 ΤΫϦϓε߈ܸͱ͔γϏϧ߈ܸͱ͔ ΠϯηϯςΟϒઃܭɾΨόφϯε
56. 56 ࣮࣌ؒੑ 1.  ΫϥΠΞϯτɾαʔόʔܕͷγεςϜͷ༻ʹɺҰ੪ʹಉ͡৘ใΛ ڞ༗͢Δ͜ͱ͕Ͱ͖ͳ͍ɻP2PωοτϫʔΫ্Ͱϝοηʔδͷૹ৴ Λ܁Γฦ͚ͩ͢Ͱ͸ɺ৘ใ͕શϊʔυʹߦ͖౉Δ·Ͱʹ͕࣌ؒ ֻ͔ͬͯ͠·͏ɻ 2.  ϑΝΠφϦςΟʔཱ͕֬͠ͳ͍ɻʢPoSͳͲͰ͸վળ͕ݟΒΕΔɻʣ ͨͩ͠ɺͦΕΛߟྀͯ͠ϏδωεϞσϧΛߟ͑Δ͜ͱ͸༗ޮɻ ϦΞϧλΠϜੑΛ΋ͱΊΒΕΔྖҬͰ͸·ͩԠ༻͕೉͍͠ɻ A→B A→BͷऔҾ͸ԿΛ΋ͬͯ׬ྃͨ͠ʢ΋͏෴Δ͜ͱ͸ͳ͍ʣͱ͍͑Δͷ͔ʁ 6ݸϒϩοΫ͕ଓ͚͹վ͟Μ͸ʢ΄΅ʣෆՄೳͱݴΘΕ͍ͯΔ͕ͦΕ·Ͱʹ60෼΋·ͨͳ͚Ε͹͍͚ͳ͍ʁ
57. 57 ˎReference : Finality Invalid Invalid • The majority decision is represented by the longest chain, which has the greatest proof-of-work effort invested in it. • Nodes always consider the longest chain to be the correct one and will keep working on extending it. Satoshi Nakamoto (2008)
58. 58 ʲ+αʳϑΝΠφϦςΟʔΛਂ۷ͬͯΈΔ ϑΝΠφϦςΟʔཱ͕֬͠ͳ͍͜ͱ΁ͷ߈ܸͱ൓࿦ https://blog.ethereum.org/2016/05/09/on-settlement-finality/ Ethereumͷ։ൃऀ Vitalikͷ൓࿦ ʮύϒϦοΫͳϒϩοΫνΣʔϯͰ͸ઃܭཧ࿦্ ͋͘·Ͱཱ֬తʹ͔͠ϑΝΠφϦςΟʔ͕ಘΒΕ ͳ͍ͷͰ̍̌̌ˋͷϑΝΠφϦςΟ͸ಘΒΕͳ͍ɻ ۚ༥ػ͕ܾؔࡁͳͲͷ༻్ʹར༻͢Δ͜ͱ͸ ৴པͷ؍఺ͰΉ͔͍ͣ͠ʯ ͦ΋ͦ΋ɺશͯͷϑΝΠφϦςΟʔ͸ཱ֬త ͳ΋ͷͰ͋ΔɻEthereumͰ͸CasperͰ51%ͷ ͖͍͠஋͸66%ʹ͍͋͛ͯΔɻ
59. 59 ൿಗੑ 2छྨͷൿಗੑ 1. ʮΞΧ΢ϯτʯͱʮݸਓʯ͕ʢ͋͑ͯʣඥ෇͍͍ͯͳ͍͜ͱʹΑͬͯى͜Δ໰୊ɻ MoneroͳͲ͸ҋऔҾʹ࢖ΘΕΔ͜ͱ͕͓͓͍Β͍͠ɻΠΪϦεͷݚڀػؔʹΑΔͱ ϏοτίΠϯͷҋऔҾ͸શମͷ0.61%ʹ͔͠ຬͨͳ͍ɻ “According to the study, the total percentage of identified “dirty bitcoins” going into conversion services was relatively small. Only 0.61 percent of the money entering conversion services during the four years analyzed were verifiably from illicit sources, with the highest proportion (1.07 percent) seen in 2013. 2. Aͱ͍͏ΞΧ΢ϯτ͔ΒBͱ͍͏ΞΧ΢ϯτʹ͍͘Βૹ͍ۚͯ͠Δ͔͕෼͔ͬͯ ͠·͏ͱ͍͏໰୊ɻͦΕࣗମʹ໰୊͸ͳ͍͕ɺૹֹۚΛ஌ΒΕͨ͘ͳ͍Ϣʔβʔ΋ ͍ΔɻʢZK-SNARKsͳͲͷղܾࡦ΋͋Δɻʣ Source : https://coincenter.org/link/a-new-study-finds-less-than-1-of-bitcoin-transactions-to-exchanges-are-illicit?utm_ content=bufferad122&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer
60. 60 3. εέʔϥϏϦςΟʔ εέʔϥϏϦςΟʔͷྫɿ ͍ͭ΋10ਓฒΜͰ͍ΔATM͕Ұ୆͋Δɻ ͜͜Ͱ৽ͨʹATMΛҰ୆଍͢ͱฒΜͰ͍Δਓ͸ Ͳ͏ͳΔͰ͠ΐ͏ʁ
61. 61 3. εέʔϥϏϦςΟʔ A. 0ʹͳΔɻʢʹۙͮ͘ʣ αʔόʔΛ௥Ճ͢Δ͜ͱʹΑΓɺੑೳ্ͷ໰୊ΛղܾͰ͖Δɻ →γεςϜ͕εέʔϧ͢Δɻ
62. 62 εέʔϥϏϦςΟʔղܾࡦ Segwitͱ͸ʁ ͦ΋ͦ΋ɺੑೳΛ͋͛ΔҝʹͰ͖Δ͜ͱ͸ɺ ʮऔҾͷσʔλαΠζΛখ͘͢͞ΔʯorʮϒϩοΫͷେ͖͞Λେ͖͘͢Δʯͷ2ͭɻ εέʔϥϏϦςΟʔ໰୊ղܾʹ޲͚ͯɺऔҾͷσʔλαΠζ Λখ͘͞͠Α͏ͱ͠ɺτϥϯβΫγϣϯ͔Βॺ໊σʔλΛ ෼཭͠ɺwitnessͱݴΘΕΔ৽͍͠ྖҬʹ͍Ͳ͏ͤ͞Δղܾࡦɻ Segwit2Xͱ͸ʁ 2017೥11݄͝Ζʹ࿩୊ʹͳ͍ͬͯͨɻSegwitϓϥε ϒϩοΫαΠζΛ2ഒʹͯ֨͠ೲͰ͖ΔσʔλྔΛ ૿΍ͦ͏ͱ͍͏࿩ɻ
63. 63 εέʔϥϏϦςΟʔղܾࡦ ϚΠΫϩϖΠϝϯτνϟωϧͱϥΠτχϯάωοτϫʔΫ ΠϠΠϠΠϠ τϥϯβΫγϣϯ͝ͱʹɺख਺ྉΛऔΒΕͯ͠·͏ ͷ͸ݏͩɺ΋͘͠͸ɺख਺ྉҎԼͷࢧ෷Λ͢Δ࣌ʹ ϚΠΫϩϖΠϝϯτ͸࢖͑Δɻ 2ऀؒͰσϙδοτΛஔ͖ɺ ࢧ෷͍ͷҝͷνϟωϧΛ։͖ɺ ด͡Δ·Ͱͷؒͷෳ਺ճͷࢧ෷͍Λ ΦϑνΣʔϯͰ࣮ࢪ͢Δͱ͍͏ΞΠσΞɻ
64. 64 εέʔϥϏϦςΟʔղܾࡦ Alice Bob ϒϩοΫνΣʔϯ औҾͷ֬ఆʹ͕͔͔࣌ؒΔͱ͍͏ͱ͍͏໰୊͕ղܾ͢Δ͕ɺσϙδοτΛ࡞Δͷ͸ΊΜͲ͍͘͞ɻ 2ऀؒͰ։͘ͷ͕ϚΠΫϩϖΠϝϯτνϟωϧ͕ͩɺෳ਺ͷϚΠΫϩϖΠϝϯτνϟωϧΛ·͍ͨͰ ೚ҙͷ2ऀؒͷߴ଎͔ͭఆֹͷࢧ෷͍Λ࣮ݱ͢Δͷ͕Lightning Networkɻ ϚΠΫϩϖΠϝϯτνϟωϧͱϥΠτχϯάωοτϫʔΫ σϙδοτ 1BTC A to B 1BTC B to A 0.01BTC to A 0.99BTC νϟωϧΫϩʔζ ϚΠφʔ΁ࢧ෷͍
65. 65 εέʔϥϏϦςΟʔղܾࡦ ϥΠτχϯάωοτϫʔΫ https://lnmainnet.gaben.win/#
66. 66 εέʔϥϏϦςΟʔղܾࡦ ΦϑνΣʔϯͷղܾࡦ͸ɺLightning Network΍Raiden NetworkͳͲͰఏڙ͞Ε͍ͯΔɻ ΦϑνΣʔϯͱ͸ͳʹ͔ʁ ຊདྷϒϩοΫνΣʔϯ্ͷऔҾΛϒϩοΫνΣʔϯ֎Ͱߦ͏͜ͱɻ 2ͭͷύλʔϯ Մೳੑ 1. औҾॴ͕ఏڙ͢ΔΦϑνΣʔϯɻ͋͘·ͰϓϥοτϑΥʔϜʹ ґଘ͍ͯ͠Δɻ 2. Lightning Network΍Raiden NetworkɻΦϯνΣʔϯ্͔Β νϟωϧΛ։͖ɺͦͷνϟωϧ಺Ͱૹड৴Λߦ͏ɻ ΦϯνΣʔϯͰͷඵؒ7τϥϯβΫγϣϯͷ ʢΠʔαϦΞϜ͸13औҾʣΛΦϑνΣʔϯΛհ͢Δ ͜ͱͰτϥϯβΫγϣϯੑೳΛܶతʹ޲্ͤ͞Δɻ Lightning NetworkͱRaiden Network Lightning Network͸ϏοτίΠϯϒϩοΫνΣʔϯͰɺ Raiden Network͸ΠʔαϦΞϜϒϩοΫνΣʔϯͰ ࣮૷͞Εʢ͍ͯʣΔɻ
67. 67 4. ΠϯηϯςΟϒઃܭɾΨόφϯε ˎ Reference :51% Attack 67 @Berkeley Blockchain Usually, a Miner joins a pool which is a team of other miners and cooperates to mine. Miner’s share •  Currently, there are no pools which get more than 50%. •  Miners are mainly from China and the other countries which the electronic bills are so low.
68. 68 5. ͦͷଞᶃ ΤΫϦϓε߈ܸ ѱҙͷ͋ΔϊʔυʹΑΓωοτϫʔΫ͕ ෼அ͞ΕΔՄೳੑ͕͋Δɻ
69. 69 5. ͦͷଞᶄ ϒϩοΫνΣʔϯͷ໰୊Ͱͳ͘ɺcryptocurrencyͷ໰୊Ͱ͕͢ɺ Cryptocurrency͸੝Γ্͕͍ͬͯΔΑ͏ʹݟ͑ͯɺ 1%ͷϓϨʔϠʔ͕99%ͷϏοτίΠϯΛอ༗͍ͯ͠Δɻ ϚΠφʔ͕ిؾ୅ͷ͍҆தࠃʹภࡏ͍ͯ͠Δɻ ͳͲͷ໰୊఺΋͋Γ·͢ɻ
70. 70 5.ͦͷଞᶅ Bitcoinʹ࣮૷͞Ε͍ͯΔεΫϦϓτݴޠͷ੍ݶ 1.  νϡʔϦϯάͷ׬શੑͷܽ೗ 1)  Bitcoin͸ϧʔϓΛ׶͑ͯαϙʔτ͍ͯ͠ͳ͍ɻτϥϯβΫγϣϯͷݕূதʹ ແݶϧʔϓΛ͚͞ΔͨΊͩͱݴΘΕ͍ͯΔɻIfจͱҰॹʹجຊίʔυΛॻ͘͜ͱͰ ͠ͷ͛Δ͕ɺεΫϦϓτΛهࡌ͢ΔϒϩοΫνΣʔϯ্ͷεϖʔεΛۃΊͯඇޮ཰ʹ࢖͏ɻ
71. 71 ෼ࢄԽɺεέʔϥϏϦςΟʔɺ҆શੑ͸ ޓ͍ʹτϨʔͦΦϑͳͷͰ3ͭಉ࣌ʹ ຬͨ͢͜ͱ͸ۃΊͯ೉͍͠ɻ
72. 72 BitcoinҎ֎ͷϒϩοΫνΣʔϯج൫ ໊শ ։ൃݩ ಺༰ Bitcoin Core Bitcoin Foundation ϏοτίΠϯͷϦϑΝϨϯε࣮૷ɻ Ethereum Ethereum Foundation DappsͷߏஙϓϥοτϑΥʔϜɻSolidityͰίϯτϥΫτ Λهࡌ͢Δɻ HyperLedger Fablic HyperLedger Project Linux FoundationओಋɻύϑΥʔϚϯε΍৴པੑͷ޲্ ͷҝʹಠࣗͷίϯηϯαεΞϧΰϦζϜ΍ϝϯόγοϓ ؅ཧΛߦ͏ɻ Corda R3 CEV R3ओಋͷۚ༥ػؔ޲͚ͷ෼ࢄܕ୆ாɻ Chain Open Standard 1 Chain.inc ୹࣌ؒͰऔҾΛ׬ྃͤ͞ΔΞϧΰϦζϜͳͲΤϯλʔϓ ϥΠζ޲͚ɻ mijin ςοΫϏϡʔϩ ϓϥΠϕʔτܕϒϩοΫνΣʔϯͰτϥϯβΫγϣϯॲ ཧͷߴ଎ԽΛ࣮ݱɻࢀՃऀ͸ڐՄ੍ͰPoSΛ࠾༻ɻ Orb1 Orb ϑΝΠφϦςΟʔʹڧΈɻதԝूݖͱ෼ࢄܕΛ༥߹ͤ͞ ͍ͯΔɻ Eris Eris Industries Ethreum͔Β೿ੜɻύʔϛογϣϯܕͷϒϩοΫνΣʔ ϯΛࢤ޲ɻ
73. ΠʔαϦΞϜ
74. 74 By ConsenSys
75. Bitcoinͱͷҧ͍ 75 ΠʔαϦΞϜʹ͸Externally Owned AccountʢEOAʣͱίϯτϥΫτΞΧ΢ϯτ͕͋Δɻ ΞΧ΢ϯτɺGasɺEVMʢEthereum Virtual Machineʣɺstatuesͱ͍͏֓೦͕༗Δɻ ΞΧ΢ϯτ Gas EVM Status ΠʔαϦΞϜͷτϥϯβΫγϣϯΛ࣮ߦ͢ΔͨΊͷख਺ྉɻ ΠʔαϦΞϜωοτϫʔΫ্Ͱಈ͘Ծ૝ϚγϯɻEVM্Ͱ͸solidityΛEVM༻ͷόΠτίʔυʹ ௚ͯ͠τϥϯβΫγϣϯΛ࣮ߦ͍ͯ͠Δɻ τϥϯβΫγϣϯ͕ى͖Δલ͸ɺ࢝·Γͷঢ়ଶʢgenesis state)Ͱ͋Γɺ৽ͨͳτϥϯβΫγϣϯͷੜ੒͝ͱʹঢ়ଶ1ɺঢ়ଶ2ɺɺɺͱมԽ͍ͯ͘͠ͷͰ͢
76. 76 ΞΧ΢ϯτ ΠʔαϦΞϜʹ͸Externally Owned AccountʢEOAʣͱίϯτϥΫτΞΧ΢ϯτ͕͋Δɻ EOA Externally Owned Account͸Ϣʔβʔͷൿີ伴ʹ Αͬͯ؅ཧ͞ΕͨΞΧ΢ϯτɻ Ϣʔβʔ͸EOAΛ௨ͯ͠ΠʔαϦΞϜ ωοτϫʔΫͱ௨৴Λߦ͏ɻίʔυ͸࣋ͨͳ͍ɻ ίϯτϥΫτΞΧ΢ϯτ ίϯτϥΫτΞΧ΢ϯτ͸ίʔυΛ࣋ͭɻίϯτϥΫτ ΞΧ΢ϯτ͸Ϣʔβʔ͕࣋ͭ͜ͱ͸Ͱ͖ͣɺΠʔαϦΞϜ ্Ͱ؅ཧ͞ΕΔɻ EOA͸ൿີ伴Λ࢖ͬͯॺ໊Λ͢Δ͜ͱͰɺτϥϯβΫγϣϯΛ࡞੒͢Δ͜ͱ͕Ͱ͖ΔɻEOA͔ΒEOAɺEOA͔Β ίϯτϥΫτʹτϥϯβΫγϣϯΛ࡞Δ͜ͱ͕Ͱ͖ΔɻEOA͔ΒEOA΁ͷτϥϯβΫγϣϯ͸ૹۚͳͲϏοτίΠϯ ͱಉ༷ɻEOA͔ΒίϯτϥΫτΞΧ΢ϯτ΁ͷτϥϯβΫγϣϯ͸ίϯτϥΫτ͕΋͍ͬͯΔίʔυΛ࣮ߦ͢Δɻ ʢ஫ʣίϯτϥΫτΞΧ΢ϯτࣗମ͸τϥϯβΫγϣϯΛ࡞Δ͜ͱ͕Ͱ͖ͳ͍ɻͨͩ͠ɺEOA͔Βͷࢦࣔ࣍ୈͰ ίϯτϥΫτΞΧ΢ϯτ͔ΒίϯτϥΫτΞΧ΢ϯτʹτϥϯβΫγϣϯΛੜ੒͢Δ͜ͱ͕Ͱ͖Δɻ
77. 77 Gas Gas͸ΠʔαϦΞϜͷτϥϯβ ΫγϣϯΛ࣮ߦ͢Δͷʹ͔͔Δ ख਺ྉɻ Gasʢख਺ྉʣ͸ϚΠφʔ͕ಘ Δ͜ͱ͕Ͱ͖ɺߴ͍ख਺ྉ΄Ͳ ϚΠφʔ͕༏ઌͯ͠ϒϩοΫʹ ؚΊΔͷͰͦͷτϥϯβΫγϣ ϯ͕ݕূ͞ΕΔ·Ͱͷ͕࣌ؒૣ ͘ͳΔɻ
78. 78 ICO ICOͷ࢓૊Έࣗମ͸޷͖Ͱ͕͢ɺ ੈͷதʹग़͍ͯΔICOͷ΄ͱΜ Ͳ͸ݏ͍Ͱ͢ɻ τʔΧφΠζ͢Δඞཁͷͳ͍ձ ࣾ·ͰICO͍ͯ͠Δݱঢ়͸݈શ Ͱ͸ͳ͍Ͱ͢ɻ ϒϩοΫνΣʔϯΛΑ͘෼͔ͬ ͍ͯͳ͍ਓ΄ͲICOɺICOݴͬ ͍ͯΔؾ͕͠·͢ɻ ͔͠͠ɺҰํͰελʔτΞοϓ ͷࢿۚௐୡखஈΛ৽͘͠੾Γ։ ͍ͨͷ΋ࣄ࣮Ͱ͢ɻ
79. 79 ZK-SNARKs ZK-SNARKs͸ΠʔαϦΞϜϒϩοΫνΣʔϯͷ ϓϥΠόγʔͷ໰୊ʹؔ͢Δղܾࡦ ZK-SNARKsͱ͸ͳʹ͔ʁ Ͳ͏͍͏࣌ʹ࢖͑Δͷ͔ʁ εϚʔτίϯτϥΫτ্ͷݸਓ৘ใ΍ اۀൿີΛϒϩοΫνΣʔϯ্ͷެ։͢Δ͚Ͳ ൿಗԽ͍ͨ࣌͠ ChronicledͷMediLedgerʢҩྍܥʣϓϩδΣΫτ Ͱ͸ɺෳ਺ͷ੡ༀձࣾͷαϓϥΠνΣʔϯΛ ϒϩοΫνΣʔϯͰ؅ཧ͢Δ࣌ʹɺ ڝ߹ʹରͯ͠ༀ඼ͷ಺༰ΛൿಗԽ͍ͨ͠ͷͰ ͜ͷٕज़Λ࢖͍ͬͯΔɻ Կ͕Ͱ͖ΔΑ͏ʹͳΔͷ͔ʁ ҰൠతͳτϥϯβΫγϣϯͰ͸ɺA͔ΒBʹ10BTCͱ͍͏ Α͏ͳτϥϯβΫγϣϯͷ಺༰Λୈࡾऀ͕֬ೝ͢Δ͜ͱ͕ Ͱ͖ΔɻZK-SNARKsΛ࢖͏ͱɺૹ৴ऀɺड৴ऀɺૹֹۚۚ ΛൿಗԽ͢Δ͜ͱ͕Ͱ͖Δ͕ɺτϥϯβΫγϣϯʹෆਖ਼͕ ͳ͍͜ͱ͸ୈࡾऀ͕֬ೝͰ͖Δɻ Zero Knowledge – Succinct Non-interactive ARgument of Knowledge ৄࡉ͸͜ͷهࣄ͕Φεεϝ https://zoom-blc.com/what-is-ethereum-zk-snark
80. 80 ZK-SNARKs ͳΜ͔ڭ͑ͯ΋ΒͬͨSNARKsͷྺ࢙ The first construction of a zero knowledge succinct argument dates back to a paper of Joe Kilian from 1992. After that, a paper of Silvio Micali in 1994 showed how to make the proof non-interactive via cryptographic hash functions. While Micali did not study zero knowledge in his paper, the community views his construction, in hindsight, as the first "zk-SNARK”. However modern constructions of zk-SNARKs did not arise until 20 years later. In a paper with co-authors and I in 2012, we coined the term "SNARK" and "zk-SNARK" and showed various alternative constructions to the classical constructions (our motivations mostly had to do with the cryptographic assumptions inherent to constructing SNARKs). Research on SNARKs since 2012 has boomed, with works studying either theoretical aspects (existence, asymptotics) or practical ones (efficient implementations, reducing high-level program representations to low-level representations "understood" by these proof systems). If I had two name two landmark papers that are direct precursors of most of today's practical SNARKs would be a paper with co-authors and I in 2013 that built a system for proving executions of arbitrary programs, and a paper of other colleagues that introduced many useful techniques still used today. But that was 4 years ago, and since then much has happened and zk-SNARK history is still being written, as every year we see new approaches and techniques that improve both our theoretical and practical understanding of them.
81. Ϗδωεతͳ ࢹ఺
82. 82 Market Cap As of mid December 2016… The market cap of all cryptocurrencies totaled $15B As of mid December 2017… The market cap of all cryptocurrencies totaled $500B An increase of 3200%. Source : CB Insights
84. 84 ΨʔτφʔͷϋΠϓɾαΠΫϧ ւ֎ ೔ຊ Blockchain
85. 85 ༗๬ͳϒϩοΫνΣʔϯ50ࣾௐ΂·ͨ͠ɻ https://www.slideshare.net/SotaWatanabe/blockchain-startup-79596749
86. 86 ݸਓతʹ஫໨͍ͯ͠ΔελʔτΞοϓᶃ
87. 87 ݸਓతʹ஫໨͍ͯ͠ΔελʔτΞοϓᶄ
88. 88 ݸਓతʹ஫໨͍ͯ͠ΔελʔτΞοϓᶅ
89. 89 ݸਓతʹ஫໨͍ͯ͠ΔελʔτΞοϓᶆ
90. 90 ݸਓతʹ஫໨͍ͯ͠ΔελʔτΞοϓ ΋ͪΖΜɺChronicled΋ʂ ͜ͷલɺաڈͷϓϩδΣΫτ೔ຊޠͰ঺հ͍ͯ͠ΔϖʔδΛ࡞ͬͨͷͰੋඇݟͯΈ͍ͯͩ͘͞ʂ ͔͜͜Βɹ: ɹhttps://www.chronicled.org/japanese/home-japanese
91. 91 ϒϩοΫνΣʔϯͬͯඞཁͳΜ͚ͩͬʁ σʔλϕʔε͸ඞཁ͔ʁ ϒϩοΫ νΣʔϯ ͡Όͳ͘ ͯྑ͘ͳ ͍ʁ Y N ෳ਺ͷεςʔΫϗϧ μʔ͕ؔΘΔ͔ʁ Y ͦΕΒͷεςʔΫϗϧμʔ͸৴པ Ͱ͖Δ͔ʁ Y ͦΕΒΛ౷߹͢Δ͜ͱ͸Ͱ͖Δ ͔ʁ Y N N N ୈࡾऀΛ৴པͰ͖Δ͔ʁ Y N ϒϩοΫνΣʔϯΛ ಋೖ͢Δίετͱޮ ༻͸ׂʹ͋͏͔ʁ N Y ϒϩοΫ νΣʔϯ ࢖͓͏ ͔ʂ ࣗ෼͕ϒϩοΫ νΣʔϯ্ͷه࿥Λ ॻ͍ͨΓಡΜͩΓΛ ͢Δඞཁੑ͸͋Δ ͔ʁ ࢀߟɿDistributed.comɹBlockcahin Capital LLC Y N ίϯηϯαε͸ෳ਺ ͷϓϨʔϠʹΑͬͯ ܾఆ͞ΕΔʁ Y N ޮ཰ΑΓ΋ɺվ͟Μ ଱ੑ΍ΞΫηαϏϦ ςΟʔͷํ͕େࣄʁ N ίϯιʔγ ΞϜ ϒϩοΫ νΣʔϯʂ ϓϥΠϕʔ τ ϒϩοΫ νΣʔϯʂ ύϒϦοΫ ϒϩοΫ νΣʔϯʂ Y
92. ݸਓతͳࢥ૝
93. ॻ͖·ͨ͠ɻ 93 https://medium.com/@watanabesouta/blockchain%E3%81%AB%E4%BA%BA%E7%94%9F%E3%82%92%E8%B3%AD%E3% 81%91%E3%82%8B%E7%90%86%E7%94%B1-1d952748ad0
94. ਓछɺੑผɺफڭɺࠃ੶ɺ਌ͷ೥ऩͳͲʹ ؔΘΒͣɺ୭΋͕ࣗ෼ͷՄೳੑΛ௥ٻͰ͖Δ ࣾձΛ૑Γ͍ͨɻ ϒϩοΫνΣʔϯΛ࢖͑͹ɺਅʹ຤୺ͷਓʑ͕ ྗΛ࣋ͭࣾձ͕Ͱ͖ΔͷͰ͸ͳ͍͔ͱࢥ͍ͬͯ·͢ɻ
95. 95 ྫ͑͹ɺɺɺɺɺɺɺ ωύʔϧ஍਒ͷ࣌ͷࣸਅ ͦ΋ͦ΋՟ฎͬͯࠃͷ৴པΛݩʹՁ஋ ͕ܾ·ΔͷͰฏ౳Ͱ͸ͳ͍ɻ
96. ͜Ε͔Β
97. 97 97 1760ʙ1830 1865ʙ1900 1990ʙ2000 ᶃGPT=Steam Engine ᶄGPT=Internal Combustion Engine ᶅGPT=Internet GPT(General Purpose Technologyʣ )JTUPSZ
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    2029 2045 ᶆGPT=AI 1st industrial revolution 2nd industrial revolution 3rd industrial revolution 4th Industrial revolution 2045 Singularity ᶇBlockchain Here ੈքͷσʔλྔ͸1೥Ͱ1.4ഒͣͭ૿͍͑ͯΔɻ͜Ε͸2೥Ͱ΄΅2ഒʹͳΔͱ͍͏͜ͱɻ AIͷ̍൪ಘҙͳͷ͸Πϯϓοτͷ࠷దԽɻσʔλ͕ੈͷதʹे෼ʹ͋ͬͨΒ ΋ͬͱ΋࠷దԽ͞Εͨࣾձ͸ͳΜͩΖ͏͔ʁ ෼ࢄԽ͔ͭࣗ཯తͳࣾձʹͳΔͱࢥ͏ɻ ͦͯͦ͠Ε͸ɺϒϩοΫνΣʔϯͷ࠷΋ಘҙͱ͢Δͱ͜ΖͰ͸ͳ͍ͩΖ͏͔ʁ
98. 98 ʙ
    T
    
    Big Picture
99. 99 ʲ+αʳDecentralizationͷఆٛ Distributedͱ Distributed͸Vitalik͕ԼهͷϒϩάͰݴ͍ͬͯ·͕͔͢ͳΓ݁ߏᐆດͰ͢ɻ https://medium.com/@VitalikButerin/the-meaning-of-decentralization-a0c92b76a274 (De)centralizationͷ3ͭͷܗ Source : consenSys
100. 100 ʲ+αʳDecentralizationͷఆٛ ʢDe)centralizationͱϒϩοΫνΣʔϯ Politically decentralizedɺarchitecturally decentralized͚ͩͲɺ logically centralizedͰ͸ͳ͍ΑͶɻͱ͍͏ͷ͕ϒϩοΫνΣʔϯɻ Source : consenSys
101. 101 ʲ+αʳDecentralizationͱWeb3 Currently, companies like Google, Facebook, and Amazon dominate the internet. They offer many free and cheap services because they are able to collect valuable data on their users, and find ways to monetize that data. As users of the modern internet, one is never too sure where their demographic and personal data is being used. Through the implementation of decentralization, also called Web3, data doesn’t have to be stored in centralized systems. Data can be verified independently and content creators are valued by the quality of their work.
102. 102 ଟ͘ͷେن໛ωοτϫʔΫ͸ྨࣅͨ͠ܗΛ੒͢ʁ ࣗݾ૊৫Խܥͱݴͬͨ΄͏͕ྑ͍͔΋͠Εͳ͍ɻ http://www.pnas.org/content/102/41/14497.full →͜ͷ࿦จతʹݴ͏ͱɺকདྷ͸ϓϥΠϕʔτνΣʔϯɺίϯιʔγΞϜνΣʔϯΛϝΠϯʹ ͦΕΛܨ͙ɺInter Ledger Protocol͕伴Λʹ͗ΔͷͰ͸ͳ͍͔ʁ
103. 103 ଟ෼͜͏ͳΔͱࢥ͏ɻ ༷ʑͳαʔϏεΛ౷߹͢ΔϒϩοΫνΣʔϯ͕ݱΕΔɻ՟ฎܦࡁ͸ਰୀ͠ɺ ৴༻ʹجͮ͘औҾ͕ߦΘΕΔΑ͏ʹͳΔͷͰ͸ͳ͍͔ʁ10೥͘Β͍͔͔Δͱࢥ͏ɻ
104. 104 Two-Way PegαΠυνΣʔϯ ࠓޙɺϒϩοΫνΣʔϯͱϒϩοΫνΣʔϯΛͲ͏ޓ׵ੑΛ࣋ͨͤΔ͔ͱ͍͏ٞ࿦͕΋ͬͱ׆ൃʹͳͬ ͯ͘Δ͸ͣɻैདྷ͸ϝΠϯνΣʔϯ→αϯυνΣʔϯͷҰํ௨ߦ͕ͩͬͨ͜Ε͕ɺ૒ํ޲ʹͳΔɻ
105. 105 Cosmosͱ͸ʁ ϒϩοΫνΣʔϯؒͷޓ׵ੑͷແ͍໰୊Λ͍͔ʹͯ͠ղܾ͢Δ ୅දతͳϓϩδΣΫτͷ1͕ͭCosmosɻऔҾॴΛܦ༝ͤͣʹɺτʔΫϯͷૹड৴͕Ͱ͖Δɻ Cosmos Hub Zone Zone Zone Zone Zone Zone
106. 106 ʮࢿຊʯ͔ΒʮՁ஋ʯͷ࣌୅΁ ͍··Ͱݟ͑ͳ͔ͬͨ΋ͷ͕ՄࢹԽͰ͖ΔΑ͏ʹͳ͖ͬͯͨɻ EX. ؔ৺΍৴པ ࠓɺ๻ͨͪ͸ࢿຊओٛͷ࣌୅ʹੜ͖͍ͯΔ͚Ͳɺ௕͍໨ͰݟΕ͹ ͜ͷલ·ͰङΓΛͯ͠ੜ͖͖ͯͨΘ͚Ͱɺ৽͍͠γεςϜ͕ੜ·Ε͖ͯͯ΋ ͓͔͘͠ͳ͍͠ɺͦΜͳ࣌୅ͷస׵఺ʹ͍ΔΑ͏ͳؾ͕͢Δɻ