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Blockchain Technologies : Landscape and Future Directions

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RISQ - Colloque 2018
15h25
Jeremy Clark

Published in: Technology
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Blockchain Technologies : Landscape and Future Directions

  1. 1. Jeremy Clark Blockchain Technology: Landscape & Future Directions
  2. 2. Jeremy Clark • Assistant Professor at the Concordia Institute for Information Systems Engineering (CIISE) in Montreal • PhD from the University of Waterloo (2009) • Team of eight graduate students • Numerous academic papers on Bitcoin/Blockchain, including one of the earliest • Contributed to courses (Princeton, MIT) & textbook on Bitcoin/blockchain • Testified to Senate and House committees on Bitcoin/blockchain Where I Am
  3. 3. Digital Revolution Blockchain
  4. 4. Digital Revolution For business processes based on paper records, digitization increases efficiency
  5. 5. 🚢
  6. 6. 🚢
  7. 7. 🚢
  8. 8. 🚢
  9. 9. 🚢
  10. 10. 🚢
  11. 11. Digital Revolution
  12. 12. Database Digital Revolution
  13. 13. T-2351 T-4528 T-9636 T-9833
  14. 14. T-2351 T-4528 T-9636 T-9833 Who Owns the Database? Privileged Position Availability Manage Access
  15. 15. T-2351 T-4528 T-9636 T-9833 Who Owns the Database? Privileged Position Availability Manage Access Reconciliation
  16. 16. T-2351 T-4528 T-9636 T-9833
  17. 17. T-2351 T-4528 T-9636 T-9833 T-2351 T-4528 T-9636 T-9833 T-2351 T-4528 T-9636 T-9833 T-2351 T-4528 T-9636 T-9833
  18. 18. T-2351 T-4528 T-9636 T-9833 T-2351 T-4528 T-9636 T-9833 T-2351 T-4528 T-9636 T-9833 T-2351 T-4528 T-9636 T-9833 Disintermediation
  19. 19. T-2351 T-4528 T-9636 T-9833 T-2351 T-4528 T-9636 T-9833 T-2351 T-4528 T-9636 T-9833 T-2351 T-4528 T-9636 T-9833 Blockchain
  20. 20. T-2351 T-4528 T-9636 T-9833 T-2351 T-4528 T-9636 T-9833 T-2351 T-4528 T-9636 T-9833 T-2351 T-4528 T-9636 T-9833 Blockchain Data cannot be changed once written Data is only written if it is true (truth by definition) Everyone sees the same data; no reconciliation Data is readily available
  21. 21. T-2351 T-4528 T-9636 T-9833 T-2351 T-4528 T-9636 T-9833 T-2351 T-4528 T-9636 T-9833 T-2351 T-4528 T-9636 T-9833 Blockchain Data cannot be changed once written Data is only written if it is true (truth by definition) Everyone sees the same data; no reconciliation Data is readily available Data can activate processes which are validated
  22. 22. • Securities: stocks, bonds, derivatives, swaps, repos and post-trade settlement • Markets: land deeds, carbon credits • Banking: inter-bank settlement, international payments, remittances, micropayments, loyalty • Provenance: luxury goods, organic certifications, supply chain management • Government: voting, registries • Coordination: internet of things • Identity management: KYC, PKI • Fun: gambling, prediction markets Use Cases
  23. 23. • Securities: stocks, bonds, derivatives, swaps, repos and post-trade settlement • Markets: land deeds, carbon credits • Banking: inter-bank settlement, international payments, remittances, micropayments, loyalty • Provenance: luxury goods, organic certifications, supply chain management • Government: voting, registries • Coordination: internet of things • Identity management: KYC, PKI • Fun: gambling, prediction markets Use Cases Blockchain systems can interact
  24. 24. Frequently Asked Questions & common misconceptions
  25. 25. Relation to Bitcoin Bitcoin is designed to be a currency (BTC) Bitcoin is not a digital form of an existing currency Thus not like Paypal, EFTs, interact-by-email Bitcoin is decentralized: no central bank
  26. 26. The term blockchain 1) Bitcoin’s protocol for achieving a distributed ledger maintained by an open network of profit- seeking nodes 2) Any distributed ledger 3) The philosophy behind Bitcoin: digitizing commodities, securities, deeds, contracts…
  27. 27. • Blockchains and (distributed) databases are similar and somewhat interchangeable • The emphasis is on different things • Blockchains are for small data (1MB every 10 min) • Blockchains are for validated data • Blockchains are not about complex queries (you download everything) • Blockchains are secure against malicious nodes Blockchain v. Database
  28. 28. • CAC-ISO-TC307: Blockchain and electronic distributed ledger technologies • Industry Consortiums: Various Standards Regulation • Use-Case Specific: Mostly pertains to Bitcoin • Taxation: capital gain • Accounting (IFRS): intangible asset • KYC/AML: Fintrac given authority • ICOs/Trusts/Exchanges: Securities authorities
  29. 29. • By default, blockchains have no confidential transactions • Confidentiality can be added on with encryption but non-trivial • By default, blockchains have no identities associated to transactions • Identities can be added (or conversely, anonymity strengthened) Confidentiality & Privacy
  30. 30. Consistency? Consensus through voting Proof of Work
  31. 31. Consistency? Consensus through voting Honest majority
  32. 32. Consistency? Consensus through voting One vote per ________? Honest majority
  33. 33. Consistency? Consensus through voting One vote per ________? 1) Entity: trusted list of entities, closed network Honest majority
  34. 34. Consistency? Consensus through voting One vote per ________? 1) Entity: trusted list of entities, closed network 2) Unit of computational effort: Bitcoin’s blockchain No trust, open network Honest majority
  35. 35. ACM Queue
  36. 36. 1980 1985 1990 1995 2000 2005 2010 2015 smart contracts public keys as identities Byzantine fault tolerance proof of work digital cash Merkle Tree [33] Haber & Stornetta [22] Haber & Stornetta [23] Benaloh & de Mare [6] Bayer, Haber, Stornetta [5] Ecash [10] anti-spam[15] hashcash [2] Micro- mint [44] client puzzles [25] offline Ecash [32] DigiCash Byzantine Generals [27] Paxos [28] PBFT [8] Paxos made simple [29] computational impostors [1] Chaum anonymous communication [9] Chaum security w/o identification [11] b-money [13] Bit gold [42] private blockchains Bitcoin [34] Ethereum Szabo essay [41] Goldberg disser- tation [20] Sybil attack [14] Nakamoto concensus linked timestamping, verifiable logs
  37. 37. More resources
  38. 38.   Bitcoin and Cryptocurrency Technologies    Arvind Narayanan, Joseph Bonneau, Edward Felten,   Andrew Miller, Steven Goldfeder    with a preface by Jeremy Clark  Draft — Feb 9, 2016    Feedback welcome! Email ​bitcoinbook@lists.cs.princeton.edu    For the latest draft and supplementary materials including programming assignments,   see our ​Coursera course​.    The official version of this book will be published by Princeton University Press in 2016.  If you’d like to be notified when it’s available, please sign up ​here​. 
  39. 39. ACM Queue
  40. 40. @PulpSpy Q

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