ブロックチェーン 2.0 / Blockchain 2.0

ブロックチェーンハブ主催で開催している連続講義 (通算第3期) ブロックチェーン基盤技術 第5回「ブロックチェーン 2.0」のスライドです。2017年3月1日(水) に使用しました。

Transcript

1. 2.0 5 SFC / CSO ks91@sfc.wide.ad.jp 2.0 — 5 — 2017-03-01 – p.1/47
2. 2.0 / Segregated Witness Proof of Stake 2.0 — 5 — 2017-03-01 – p.2/47
3. 2.0 1. 2. 3. 4. 2.0 — 5 — 2017-03-01 – p.3/47
4. 1. Abra – Uber – as is Proof of Existence – – (1) Everledger, Factom – – (2) 2.0 — 5 — 2017-03-01 – p.4/47
5. Abra Uber https://www.goabra.com Abra cf. Uber cf. Airbnb 2.0 — 5 — 2017-03-01 – p.5/47
6. Abra P2P ( ) ( ) (teller) → ATM → ATM BTC 2.0 — 5 — 2017-03-01 – p.6/47
7. Abra 1.5% Abra 0.25% Abra (by CEO) 2.0 — 5 — 2017-03-01 – p.7/47
8. BTC (USD 3 ) Abra UI (2015 ) “Don’t lose your phone!” ( ) Abra 2.0 — 5 — 2017-03-01 – p.8/47
9. Proof of Existence ( ) https://proofofexistence.com 2.0 — 5 — 2017-03-01 – p.9/47
10. Proof of Existence ( ) ( ) OP_RETURN OP_RETURN = ⇒ (burn = ( ) ) 0x444f4350524f4f46 (‘DOCPROOF’) SHA-256 Bitcoin blockchain explorer 5 mBTC (0.005 BTC) 2.0 — 5 — 2017-03-01 – p.10/47
11. – Everledger https://www.everledger.io Factom https://www.factom.com (Merkle ) 2.0 — 5 — 2017-03-01 – p.11/47
12. ( KVS DHT) 2.0 — 5 — 2017-03-01 – p.12/47
13. 2. Segregated Witness 2.0 — 5 — 2017-03-01 – p.13/47
14. BTC / . . . 2.0 — 5 — 2017-03-01 – p.14/47
15. EPOBC (Open Assets) OP_RETURN 2.0 — 5 — 2017-03-01 – p.15/47
16. Open Assets Protocol (OAP) ( = ) 2.0 — 5 — 2017-03-01 – p.16/47
17. ID ID (asset ID) 1. 2. 3. 160 = ID ( ) 4. base58check ‘A’ ( = 23) (asset quantity) BTC 2.0 — 5 — 2017-03-01 – p.17/47
18. OP_RETURN PUSH 0x4f41 (‘OA’) = 2 0x0100 2 1∼9 LEB128 1∼9 2.0 — 5 — 2017-03-01 – p.18/47
19. 2.0 — 5 — 2017-03-01 – p.19/47
20. Segregated Witness ( = ) (malleability) 2.0 — 5 — 2017-03-01 – p.20/47
21. (witness) 2.0 — 5 — 2017-03-01 – p.21/47
22. OP_RETURN PUSH 0xaa21a9ed 4 (witness) SHA-256 32 Merkle 2.0 — 5 — 2017-03-01 – p.22/47
23. (1) P2WPKH (version 0) (pay-to-(witnessed)-public-key-hash) witness ( ): < > < > scriptSig ( ): scriptPubKey ( ) 0 <20-byte > 20-byte < > < > CHECKSIG 2.0 — 5 — 2017-03-01 – p.23/47
24. (2) P2WSH (version 0) (pay-to-(witnessed)-script-hash) witness: < 1 > <1 < 1 > < 2 > 2 CHECKMULTISIG> scriptSig: scriptPubKey 0 <32-byte > 32-byte 1-out-of-2 2.0 — 5 — 2017-03-01 – p.24/47
25. SegWit 2016 100 SegWit (95% ) . . . 2.0 — 5 — 2017-03-01 – p.25/47
26. 3. 2.0 — 5 — 2017-03-01 – p.26/47
27. BIP (Bitcoin Improvement Proposal) ex. BIP 1 : BIP Purposes and Guidelines https://github.com/bitcoin/bips/blob/master/bip-0001.mediawiki ex. BIP 141 : Segregated Witness (Consensus layer) TCP/IP RFC XMPP XEP 2.0 — 5 — 2017-03-01 – p.27/47
28. 4. Proof of Stake ( ) 2.0 — 5 — 2017-03-01 – p.28/47
29. Proof of Stake ( ) 2.0 — 5 — 2017-03-01 – p.29/47
30. Proof of Stake ( ) ( ) 2.0 — 5 — 2017-03-01 – p.30/47
31. Proof of Stake Hn (PD + id + t + . . .) ≤ 2n × balance d H n : n (ex. SHA-256 (n = 256)) PD : id : (ex. ) t : (ex. UNIX ( )) balance : d : (ex. ) POW 2.0 — 5 — 2017-03-01 – p.31/47
32. Proof of Stake 3 1. 2. “Nothing at Stake” 3. 51% 2.0 — 5 — 2017-03-01 – p.32/47
33. : Proof of Stake Velocity Reddcoin 2.0 — 5 — 2017-03-01 – p.33/47
34. Nothing at Stake - 2.0 — 5 — 2017-03-01 – p.34/47
35. Nothing at Stake - 100% Proof of Stake 2.0 — 5 — 2017-03-01 – p.35/47
36. 51% 2.0 — 5 — 2017-03-01 – p.36/47
37. . . . 2.0 — 5 — 2017-03-01 – p.37/47
38. 2.0 — 5 — 2017-03-01 – p.38/47
39. 2.0 — 5 — 2017-03-01 – p.39/47
40. → ⇒ A. Back, et. al., “Enabling Blockchain Innovations with Pegged Sidechains”, 2014 2.0 — 5 — 2017-03-01 – p.40/47
41. 1 1 10 2 2.0 — 5 — 2017-03-01 – p.41/47
42. A-B 2.0 — 5 — 2017-03-01 – p.42/47
43. 2 2 ( ) Ripple Path 2.0 — 5 — 2017-03-01 – p.43/47
44. 2.0 — 5 — 2017-03-01 – p.44/47
45. ( ) 1. 2. ( ) 2.0 — 5 — 2017-03-01 – p.45/47
46. OP_RETURN DNS ⇒ 2.0 — 5 — 2017-03-01 – p.46/47
47. 2.0 — 5 — 2017-03-01 – p.47/47