4 차산업혁명은 왜블록체인을찾는가?
목차 비트코인이란무엇인가? 비트코인의핵심, 블록체인 비트코인과블록체인이당면한기술적문제 4 차산업혁명, 왜블록체인을요구하는가? 블록체인의활용사례 블록체인의미래 2
비트코인이란무엇인가? 3
Bitcoin (2008) (In October 2008, posted to the Cypherpunks mailing list)
Bitcoin 은최초의암호화폐인가? (Crypto 1982)
ecash (1982) vs. Bitcoin (2008) Anonymity ( 익명성 ) Transferability ( 양도성 ) Prevent copy & double-spending ( 중복사용방지 ) Decentralized ( 분산처리 ) 6
ecash (1982) 4. Double-spending ( 중복사용 ) 감시 1477 1. Withdrawal ( 인출 ) 3. Deposit ( 예금 ) 1477 1477 1477 2. Payment ( 지불 ) Client Seller (Jannik Dreier et al., "Formal Analysis of E-Cash Protocols", SECRYPT 2015)
Bitcoin (2008) 4. Double-spending ( 중복사용 ) 감시는누가? 1. 발권은누가? 3. Deposit ( 예금 ) 1477 1477 1477 2. Payment ( 지불 ) Client Seller
Bitcoin (2008) Double Spending! 1477 1423 Double Spending! Double Spending! 1477 1423 1477 1423 1423 Client Seller
Bitcoin (2008) Double Spending! 1477 1423 Not Double Spending! Double Spending! 1477 1423 1477 1423 의견불일치! ( 일명, The Byzantine Generals Problem) 합의 가필요 1423 Client Seller
Bitcoin 중복사용을막는방법, 블록체인 1477 1423 분산장부 1477 1423 1477 1423 1477 1423
Bitcoin 중복사용을막는방법, 블록체인 분산된공개장부 + 투표 ( 합의 ) Blockchain
Bitcoin 중복사용을막는방법, 블록체인 1. 각자가관찰한 10 분간의모든거래내역을장부 ( 일명, block) 에기록 2. 회람 3. 서로다른장부가존재할경우투표 4. 선출된장부를각자보관중이던이전장부에연결해 ( 일명, chain) 보관 실제는동시에발생!
Bitcoin 에서발권을하는방법, 채굴 채굴 (mining) : Bitcoin 을얻는가장기본적인방법 14
Bitcoin 에서발권을하는방법, 채굴 인플레이션을방지하기위해약 4 년마다보상을받는가격이절반으로떨어지도록설계됨. 초기보상액은 2009 년 50 Bitcoin 이었고, 2013 년에는 25 Bitcoin, 2016 년에는 12.5 Bitcoin 이었으며, 이는계속해서줄어듬. 끊임없이반으로줄어들면최종에는약 2 천 1 백만개의 Bitcoin 만존재하게됨. 2140 년 5 월 7 일경모든 Bitcoin 이생성될것으로예측됨. 15 Block rewards Transaction fees (* But, in ACM CCS 2016, Miles Carlsten et al. showed that the stability of bitcoin is NOT guaranteed as mining rewards decline.)
Altcoin (Source: https://coin360.io/, Note: As of 17:00 July 27, 2018) 암호화폐는 2018 년 3 월 11 일기준 1,523 개가유통되고있으며, 2013 년 4 월부터약 5 년동안 2,544 개가신규발행되고 1,028 개가퇴출됨. ( 분석기간중매주평균적으로 17.1 개가신규발행되고 12.7 개가퇴출 ) 16 - 예금보험연구포럼 2018 -
Altcoin Example : Monero (2014) ( : zk-starks) [1] Bitcoin 17 Beginner, Privacy Coin Comparison, December 30, 2017 [2] Felix Küster, "Privacy Coins Guide: Comparison of Anonymous Cryptocurrencies", Aug 23, 2017
비트코인의핵심, 블록체인 18
블록체인합의기술 합의 (Ⅰ) A B C D E 19
블록체인합의기술 합의 (Ⅰ) A B C D E 20
블록체인합의기술 합의 (Ⅰ) A 만장일치! : 서로다른장부가존재하지않음. B C D E A 21
블록체인합의기술 합의 (Ⅰ) A B C D E A 22
블록체인합의기술 합의 (Ⅰ) A 만장일치! : 서로다른장부가존재하지않음. B C D E B (10 분 ) A 23
블록체인합의기술 합의 (Ⅰ) A B C D E B (10 분 ) A 24
블록체인합의기술 합의 (Ⅰ) A 의견불일치! : 최초로만들어져공유된장부가서로다름 B C 구성원들간의투표로결정! D E D B D (20 분 ) (10 분 ) A 25
블록체인합의기술 합의 (Ⅰ) A B C D E D B D (20 분 ) (10 분 ) A 26
블록체인합의기술 합의 (Ⅰ) A 만장일치! : 서로다른장부가존재하지않음. B C E (30 분 ) D D D (20 분 ) E (10 분 ) B A 27
블록체인합의기술 합의 (Ⅱ) (70 분 ) (60 분 ) (50 분 ) The Longest Chain Rule : 유효한장부는대다수 (>50%) 의합의가모인 ( 가장긴 ) 블록 E (40 분 ) (30 분 ) C D (20 분 ) B (10 분 ) 28 A
Safety(or Consensus Finality) vs. Liveness(or Termination) Tendermint and other PBFT-style Blockchain Bitcoin A A B C B C D E D E 29
FLP Impossibility Result Response delay? Conflict of opinion? Short delay Long delay (no upper bound on propagation delay) 30
비트코인과블록체인이 당면한기술적문제 31
Q) Decentralized( 탈중앙화 )? (1-CPU-1-Vote rule) Bitcoin 을만들당시 Satoshi Nakamoto 는모든참가자가 CPU 를이용해채굴작업을할것이라가정함. 그러나시간이지나면서특별히설계된전용채굴장비가등장하기시작함. CPU GPU FPGA ASIC 32
Q) Decentralized( 탈중앙화 )? 또한다수의채굴 (mining) 장비를보유한참가자들이뭉치면서집단화 세력화되기시작함. 33
Q) Decentralized( 탈중앙화 )? 34
Q) Decentralized( 탈중앙화 )? Neither are all that decentralized! Both Bitcoin and Ethereum mining are very centralized, with the top 4 miners in Bitcoin and the top 3 miners in Ethereum controlling more than 50% of the hash rate. 35 (Financial Cryptography and Data Security 2018)
Q) Scalability( 확장성 )? SCALABILITY ( 확장성 ) CONSENSUS ( 합의 ) 36
[Note] Private Blockchains Public / Federated / Private Scalability 독재 : 중앙집중형또는 Private Blockchains 간접민주주의 : Federated Blockchains R3, B3I, EWF, etc 직접민주주의 : Public Blockchains Consensus Bitcoin, Ethereum, Litecoin, etc 37
Q) 엄청난양의에너지낭비! 38
Q) Abusable Openness! 39
Q) Abusable Openness! (Financial Cryptography and Data Security 2018) 40 Our quantitative analysis shows that 1.4% of the roughly 251 million transactions in Bitcoin's blockchain contained data that had nothing to do with bitcoin. Among these files there may be objectionable contents such as links to child pornography, copyright violations, privacy violations, politically sensitive content, malware, etc.
4 차산업혁명, 왜블록체인을요구하는가? 41
Industry 4.0 (Digital Transformation) 1784~ 1870~ 1969~ Today~ 육체노동의기계화 전기를이용한대량생산 정보화및자동화 CPS 또는 O2O (Smart Automation) 42
Industry 4.0 (Digital Transformation) 디지털 ( 자동화 ) 과 ICT 기술 ( 초연결 ) 의광범위한힘을활용해사회전반을완전히바꾸는것! 제 3 차산업혁명이단순한디지털화라면, 제 4 차산업혁명에서는이러한변화가다양한분야에서동시다발적으로일어나상호융합하므로혁신의발전과전파속도가그어느때보다빠름. 43
Smart Manufacturing @ Industry 4.0 (Michele H.Ahuett-Garza and T.Kurfess, "A Brief Discussion on the Trends of Habilitating Technologies for Industry 4.0 and Smart Manufacturing", Manufacturing Letters, Feb 17, 2018) 44
But.. 정보의가두리양식장, O2O 플랫폼 45
우리의, 우리에의한, 우리를위한 DB CENTRALIZED DATABASE DECENTRALIZED BLOCKCHAIN CONTROLLER Centralized Database USER AGREEMENTS / TERMS OF USE CLIENTS / USERS
우리의, 우리에의한, 우리를위한 DB Business Data Analytics Artificial Intelligence (AI) Internet Of Things (IOT) Decentralized Blockchain Platform Internet
우리의, 우리에의한, 우리를위한 DB Business Data Analytics Artificial Intelligence (AI) Internet Of Things (IOT) Decentralized Blockchain Platform Internet
블록체인의활용사례 49
OpenBazaar : Free Online Marketplace (CEO & 주주들 ) (CEO & 주주들 ) (2016) 50
La'Zooz : Decentralized UBER (2014) 51
돈버는블로그, 스팀잇 (2016) ( 해피아워, " 돈버는블로그스팀잇입문후기, 2018 년 1 월 22 일 ) 52
DTube : Decentralized Tube 53
Transparency in Supply Chains : Food 54
TransparencyinSupplyChains:Logistics (DHL Trend Research, "Blockchain in Logistics", 2018) 55
TransparencyinSupplyChains:Logistics 56 ( 과학기술정보통신부, 2018 년기술영향평가결과보고 - 블록체인의미래 ", 2019)
Military 57
Electronic Voting 58
59
[Note] Voter-Verified Paper Audit Trail 60
Content s Availability 61
Content s Availability 62
PolySwarm : Decentralized Virus Total 63
Ethereum(2013) 과 DApp The World Computer : 비트코인은블록체인에화폐거래내역만저장하는반면, 이더리움은블록체인에서프로그램의코드가돌아가도록만듦. ( 현상금 (Gas) 붙은프로그램 ) (https://bytescout.com/blog/ethereum-turing-blockchain.html)
DApp : CryptoKitties (2017)
DApp : CryptoKitties (2017) By 액시엄젠 (Axiom Zen) 출시이후 1 만달러이상의고양이가 100 마리이상거래됐고, 경제규모는 4 천만달러에달했음. 심지어몇몇이용자들은 10 만달러이상의고양이를거래하기도함. 출시이후크립토키티의거래량이이더리움네트워크트래픽의약 25% 를차지하기도함 네트워크처리속도해결이관건. 66
Smart Contract Security (Feb 23, 2018) 68
Dynamic Analysis for Smart Contract 69
블록체인의미래 70
암호화폐의가치는? 토큰기반 BM 시장에서의성공여부나가능성은? 암호화폐 블록체인의여러난제들중무엇을해결했는가? 블록체인
암호화폐와블록체인의미래는? (Vincent Dieterich et al. "Application of Blockchain Technology in the Manufacturing Industry", 72 Frankfurt School Blockchain Center Working Paper, Nov. 2017)
결론 73
References [JTBC 차이나는클라스 ] 블록체인. 신세계인가? 신기루인가? https://youtu.be/8qkyfatjtya 74
References Kid Blockchain 초등학생도이해하는블록체인 http://amhoin.blog. me/221291896225 75
References 블록체인의미래 https://www.kistep.r e.kr/c5/sub2.jsp?brd Type=R&bbIdx=127 17 76
2019 by Seungjoo Kim. Permission to make digital or hard copies of part or all of this material is currently granted without fee provided that copies are made only for personal or classroom use, are not distributed for profit or commercial advantage, and that new copies bear this notice and the full citation.
4 차산업혁명은 왜블록체인을찾는가?