FinTech/LegalTech と分散システム ─ 分散システムから見たブロックチェーンの挑戦と不可能性 / FinTech, LegalTech and Distributed Systems

2016年4月26日に大阪市立大学にて講演した際に用いたスライドです。ベースとなっているのは 2月の Developers Summit 2016 での発表資料です。

Transcript

1. FinTech/LegalTech SFC Orb kenji@imagine-orb.com / ks91@sfc.wide.ad.jp FinTech/LegalTech – – 2016-04-27 – p.1/46
2. 2008 cf. FinTech (Financial Technology) cf. LegalTech (Legal Technology) FinTech/LegalTech – – 2016-04-27 – p.2/46
3. ( ) SFC ( ) Orb ( ) 1993 M.Eng ( ) 2006 ( ) DMC SFC 15 P2P ⇒ FinTech/LegalTech – – 2016-04-27 – p.3/46
4. (1) (2015) Kindle cf. FinTech/LegalTech – – 2016-04-27 – p.4/46
5. (2) (2015) Kindle . . . FinTech/LegalTech – – 2016-04-27 – p.5/46
6. 1. 2. 3. Reality Bites 4. FinTech/LegalTech – – 2016-04-27 – p.6/46
7. 1. ( ) FinTech/LegalTech – – 2016-04-27 – p.7/46
8. ( ) ( ) ← (TX) (TX) ← ( : ) ( ) “A timestamp server works by taking a hash of a block of items to be timestamped and widely publishing the hash, such as in a newspaper or Usenet post” “To implement a distributed timestamp server on a peer-to-peer basis, we will need to use a proof-of-work system similar to Adam Back’s Hashcash, rather than newspaper or Usenet posts” – Satoshi Nakamoto (2008) FinTech/LegalTech – – 2016-04-27 – p.8/46
9. - FinTech/LegalTech – – 2016-04-27 – p.9/46
10. - RSA, DSA, ECDSA ( DSA) ( RSA ) PKI FinTech/LegalTech – – 2016-04-27 – p.10/46
11. 3 1. TX · ⇒ 2. ⇒ 3. ⇒ FinTech/LegalTech – – 2016-04-27 – p.11/46
12. . . . FinTech/LegalTech – – 2016-04-27 – p.12/46
13. ( ) 1. 10 ( ) 2. 3. 1 FinTech/LegalTech – – 2016-04-27 – p.13/46
14. ( ) FinTech/LegalTech – – 2016-04-27 – p.14/46
15. Proof of Work ( ) FinTech/LegalTech – – 2016-04-27 – p.15/46
16. Proof of Work : Hashcash (1997) SHA-1 20 ( ) 0 1 1 / FinTech/LegalTech – – 2016-04-27 – p.16/46
17. ( ) FinTech/LegalTech – – 2016-04-27 – p.17/46
18. ( ) FinTech/LegalTech – – 2016-04-27 – p.18/46
19. POW Proof Of Work ( ) . . . FinTech/LegalTech – – 2016-04-27 – p.19/46
20. 2 FinTech/LegalTech – – 2016-04-27 – p.20/46
21. Proof of Work ( ) 1∼2 ( ) ( → ) ASIC . . . FinTech/LegalTech – – 2016-04-27 – p.21/46
22. UTXO UTXO : Unspent TX Output FinTech/LegalTech – – 2016-04-27 – p.22/46
23. ( ) M A 60BTC FinTech/LegalTech – – 2016-04-27 – p.23/46
24. 2. FinTech FinTech/LegalTech – – 2016-04-27 – p.24/46
25. ( ) : . . . : Proof of Existence : DAO/DAC — ( ) : . . . FinTech/LegalTech – – 2016-04-27 – p.25/46
26. 1 (2015 ) BNY Mellon 4 UBS 4 USAA 5 DBS IBM 5 Barclays Safello 6 Deutsche Bank 8 7 BNP Paribas 7 ING Bank 7 Citi Citicoin 7 R3CEV 30 9 FinTech/LegalTech – – 2016-04-27 – p.26/46
27. 2 (2015 ) NASDAQ linq Chain.com 6 SWIFT 7 VISA 3 8 FinTech/LegalTech – – 2016-04-27 – p.27/46
28. 3 (2015 ) FRB IBM 3 5 EBA 5 FinTech 225M 7 2016 (3 ) (5 ) FinTech/LegalTech – – 2016-04-27 – p.28/46
29. e.g. e.g. (Hyperledger) (by DAH) FinTech/LegalTech – – 2016-04-27 – p.29/46
30. DAC/DAO revisted Distributed/Decentralized Autonomous Corporation/Organization - : cf. L.Lessig, “Code: And Other Laws of Cyberspace”, 1999 FinTech/LegalTech – – 2016-04-27 – p.30/46
31. Vitalik Buterin, “Ethereum White Paper: A NEXT GENERATION SMART CONTRACT & DECENTRALIZED APPLICATION PLATFORM” : FinTech/LegalTech – – 2016-04-27 – p.31/46
32. 3. Reality Bites vs. FinTech/LegalTech – – 2016-04-27 – p.32/46
33. CAP Consistency ( ) Availability ( ) Partition tolerance ( ) ⇒ 3 C Eventual consistency ( ) . . . FinTech/LegalTech – – 2016-04-27 – p.33/46
34. Consistency ( ) Strong consistency ( ) (safety) Eventual consistency ( ) (liveness) ↑ Weak consistency ( ) ← ( ) FinTech/LegalTech – – 2016-04-27 – p.34/46
35. vs. FinTech/LegalTech – – 2016-04-27 – p.35/46
36. ( ) FinTech/LegalTech – – 2016-04-27 – p.36/46
37. IoT IoT . . . ( ) I/O EVM ( ) ( ) . . . I/O cf. ADEPT by IBM ( ) FinTech/LegalTech – – 2016-04-27 – p.37/46
38. n = f ( ) ( n ) FinTech/LegalTech – – 2016-04-27 – p.38/46
39. n > 3f R F R > 2F ⇒ FinTech/LegalTech – – 2016-04-27 – p.39/46
40. P2P : P2P 3 3 FinTech/LegalTech – – 2016-04-27 – p.40/46
41. f = 1 ⇒ R FinTech/LegalTech – – 2016-04-27 – p.41/46
42. E. Heilman, et. al., “Eclipse Attacks on Bitcoin’s Peer-to-Peer Network”, 24th USENIX Security Symposium, 2015 Takuya Shibuta, “Analysis of Eclipse-Attack Vulnerability on Single Global Ledger Cryptocurrencies”, , 2015 FinTech/LegalTech – – 2016-04-27 – p.42/46
43. FinTech/LegalTech – – 2016-04-27 – p.43/46
44. 4. FinTech/LegalTech – – 2016-04-27 – p.44/46
45. / , ← 2.0 , NEM ← eris, mijin, Orb 1 ← ← (by DAH) ← Practical Byzantine Fault Tolerance ( ) FinTech/LegalTech – – 2016-04-27 – p.45/46
46. OK FinTech/LegalTech – – 2016-04-27 – p.46/46