$30 off During Our Annual Pro Sale. View Details »

World with Blockchain — and Blockchain Governance —

World with Blockchain — and Blockchain Governance —

Slides I used at my lecture in APSIG 2018 (Asia-Pacific School on Internet Governance 2018) held at Asian Institute of Technology, Bangkok, Thailand on July 10, 2018.

Kenji Saito
PRO

July 10, 2018
Tweet

More Decks by Kenji Saito

Other Decks in Technology

Transcript

  1. It Might be an Apple
    . . .
    But is it?
    World with Blockchain
    — and Blockchain Governance —
    Kenji Saito
    Keio Research Institute at SFC, Keio University / beyond-blockchain.org
    [email protected]
    World with Blockchain — and Blockchain Governance — 2018-07-10 – p.1/21

    View Slide

  2. Who Am I?
    Kenji Saito, Ph.D.
    Senior Researcher, Keio Research Institute at SFC, Keio University
    Lecturer, Faculty of Environment and Information Studies, Keio University
    Representative Director, Beyond Blockchain / Chief Science Officer, BlockchainHub Inc.
    Representative Director, Academy Camp
    Bio
    1993 : M.Eng in Computer Science from Cornell University
    2006 : Ph.D. in Media and Governance from Keio University (on digital currency research)
    Making research on P2P (peer-to-peer) and digital currencies for over 17 years
    Holding Academy Camp series for children in Fukushima since the summer of 2011, the
    year of the Great East Japan Earthquake, tsunami and the nuclear disaster
    → In my mind, they are all connected (how do we design our society hereafter?)
    World with Blockchain — and Blockchain Governance — 2018-07-10 – p.2/21

    View Slide

  3. Blockchains and Supply Chains
    Walmart, JD.com, IBM and Tsinghua University Launch a Blockchain Food
    Safety Alliance in China
    The four companies will work together to create a standards-based method of
    collecting data about the origin, safety and authenticity of food, using
    blockchain technology to provide real-time traceability throughout the supply
    chain
    This will encourage accountability and give suppliers, regulators and
    consumers greater insight and transparency into how food is handled, from the
    farm to consumers
    This has traditionally been challenging due to complex and fragmented data
    sharing systems that are often paper-based and can be error-prone
    — IBM News Release, 14 Dec 2017
    https://www-03.ibm.com/press/us/en/pressrelease/53487.wss
    ⇒ Really?
    World with Blockchain — and Blockchain Governance — 2018-07-10 – p.3/21

    View Slide

  4. What Does A Blockchain (Try to) Provide?
    1) Save and maintain records whose content and existence nobody can deny
    2) Everyone can confirm that 1) is working correctly
    3) Nobody can stop 1) or 2)
    For a specific application, “nobody” and “everyone” means among defined stakeholders
    ⇒ Virtually can fix records in the air
    ⇒ Twofold problems :
    Is it really realized? (technological problems)
    Problems in timeliness, scalability, dependability, adaptability and sustainability
    If it is really realized, can it be applied to real problems?
    How do we link firmly between the physical entity and its digital counterpart?
    · Can we trace materials after being processed in supply chains?
    → Always with socio-technical or techno-political issues
    World with Blockchain — and Blockchain Governance — 2018-07-10 – p.4/21

    View Slide

  5. What is a Blockchain?
    “The problem” Bitcoin tries to answer
    “How do I let nobody stop me from spending my own money?”
    Distrust against (central) bank money
    “The answer” Bitcoin provides
    Exchange digital coins in a P2P (peer-to-peer) manner without fixed
    servers
    Using digital signatures (to guarantee validity and non-repudiation of content)
    Need to prevent “double spending” (to guarantee non-repudiation of existence)
    ⇒ Print an evidence on “newspaper” the crowd (users) collectively issues
    Blockchains can virtually “fix promises in the air”
    Can fix records in the form of “promises” (with agreed rights) → money is both a “promise” and public goods
    Expected applicability to other public goods
    World with Blockchain — and Blockchain Governance — 2018-07-10 – p.5/21

    View Slide

  6. Beaker / Newspaper Model (1)
    Bitcoin and its blockchain in a physical model
    21M cm3 (cc) liquid in a tank
    Anyone can have as many beakers as they want, each can
    measure down to 10−8 cm3
    These beakers are placed in a public space
    Each beaker is locked by a mechanical lid, opened only
    with the participant’s private key
    Today, a selected party can take 12.5cm3 from the tank
    Selection happens every 10 minutes on average
    Selected by a special lottery
    Each party has a box with a winning ticket, and draws with
    full force
    ⇒ Faster, the more advantageous
    ⇒ Can satisfy liveness (system does not stop)
    World with Blockchain — and Blockchain Governance — 2018-07-10 – p.6/21

    View Slide

  7. Beaker / Newspaper Model (2)
    Liquid can be moved among beakers in certain ways
    (Guarantee of Validity)
    Only the corresponding private key can open a lid
    Once opened, the beaker must be emptied
    The “selected party” validates the trades, and creates a new
    page of newspaper where records are printed (Proof of Existence)
    Can also take spill (fee)
    If the same page number is used, longer sequence is valid
    (Consensus on Uniqueness)
    Often, people lose their private keys
    Let’s consider this as currency
    → Bitcoin
    (there’s no “real money”; every currency is considered as currency)
    World with Blockchain — and Blockchain Governance — 2018-07-10 – p.7/21

    View Slide

  8. Hash-chain with Proof-of-Work
    page number : n page number : n+1 page number : n+2
    Cryptographic digest of the previous page
    (must be less than or equal to the target value)
    some extra number (Nonce : Number used Once)
    (random value to make the digest less than or equal to the target)
    Cryptographic digest of a page must be less than or equal to the given target value for the page
    Can’t guess what digest is returned when the data is how modified → must be repetitively tried for many, many times
    With this “lottery”, no record can be altered unless the same amount of cost is cast
    World with Blockchain — and Blockchain Governance — 2018-07-10 – p.8/21

    View Slide

  9. Uniqueness ∼ Nakamoto Consensus
    page number : n page number : n+1 page number : n+2 page number : n+3
    page number : n+1 page number : n+2 page number : n+3
    page number : n+4
    This history is valid
    Occasionally, the sequence of pages gets separated as more than one miner win the lottery
    about the same time
    This is inevitable as autonomy is required not to let anyone stop the system
    The sequence with the highest accumulated cost of proof of work is the most difficult to alter
    Everyone agrees that the sequence is the correct history (this does not realize exact consensus)
    World with Blockchain — and Blockchain Governance — 2018-07-10 – p.9/21

    View Slide

  10. Blockchains and Distributed Ledgers Now
    Blockchains (“the air” is typically a global space)
    Bitcoin (The blockchain)
    Open Assets Protocol (OAP)
    (can define arbitrary quantities over Bitcoin blockchain to transfer)
    Ethereum (platform for so-called Distributed Apps) (experimental)
    Enterprise Ethereum Alliance (↓ evolve this way?)
    Other distributed ledgers (“the air” is typically a local space)
    Hyperledger (Linux Foundation)
    Fabric (IBM/DAH), Sawtooth (Intel), Iroha (Soramitsu),
    . . .
    many development projects are ongoing
    Corda (R3), Tangle (IOTA),
    . . .
    , BBc-1 (beyond-blockchain.org)
    Can nobody really deny the content or existence of a record?
    Can everyone really confirm the correctness of the above?
    World with Blockchain — and Blockchain Governance — 2018-07-10 – p.10/21

    View Slide

  11. Problems of Blockchains and Other Ledgers
    Lack of Timeliness (probabilistic behavior)
    Lack of Confidentiality (verifiability open to everyone)
    Oneness (distributed vs. replicated)
    Lack of Scalability (won’t scale if replicated to all participants)
    Governance Problem (can’t change if all needs to work together the exact same way)
    Incentive Mismatch (supported by the price of native currency)
    All applications may stop upon sudden drop of the price because miners would have to leave
    ⇒ Solvable if re-designed from scratch
    Ongoing (example : BBc-1)
    Many distributed ledgers are not designed from scratch
    Ex : Hash-chain without proof of work is not tamper-resistant
    Ex : In newspaper model, printing on a house magazine gives no proof
    World with Blockchain — and Blockchain Governance — 2018-07-10 – p.11/21

    View Slide

  12. Blockchains vs. Private Ledgers
    Private ledger
    Blockchain
    Verifiability
    Fault-
    tolerance
    Tamper-
    resistance
    Consistency
    Latency
    Throughput
    Resource-
    saving
    Ease of
    development
    Sustainability
    Private ledgers often lack important properties such as tamper-resistance and verifiability
    World with Blockchain — and Blockchain Governance — 2018-07-10 – p.12/21

    View Slide

  13. Beyond Blockchain One (BBc-1)
    Proof of existence is made possible even in a situation like “our customers can read our house magazine”
    Open source since 31 Oct. 2017 (v1.0 on 22 May 2018) (https://github.com/beyond-blockchain), managed by an NPO
    Beyond Blockchain, the NPO, welcomes corporate members
    World with Blockchain — and Blockchain Governance — 2018-07-10 – p.13/21

    View Slide

  14. Introducing BBc-1 — Features
    Guarantee of
    Validity
    UTXO data structure +
    separation between identifiers
    and public keys +
    validation within a domain
    Asset as a proof of debt +
    common consensus algorithms
    such as Byzantine Paxos
    No native currency +
    governance within
    a domain
    inter-crossing references +
    initially, anchoring to existing blockchains
    Proof of
    Existence
    Consensus on
    Uniqueness
    Distribution of
    Governance
    https://beyond-blockchain.org
    World with Blockchain — and Blockchain Governance — 2018-07-10 – p.14/21

    View Slide

  15. Design with Potentials
    Private ledger
    BBc-1
    Blockchain
    Verifiability
    potential
    potential
    potential
    Fault-
    tolerance
    Tamper-
    resistance
    Consistency
    Latency
    Throughput
    Resource-
    saving
    Ease of
    development
    Sustainability
    Initial design and reference software of BBc-1 can be improved in many ways
    World with Blockchain — and Blockchain Governance — 2018-07-10 – p.15/21

    View Slide

  16. References
    Web Page
    https://beyond-blockchain.org/
    GitHub
    https://github.com/beyond-blockchain
    BBc Trust (requirement specifications)
    https://beyond-blockchain.org/public/bbc-trust.pdf
    Design Paper (white paper) (currently revision 0.1)
    https://beyond-blockchain.org/public/bbc1-design-paper.pdf
    World with Blockchain — and Blockchain Governance — 2018-07-10 – p.16/21

    View Slide

  17. On Tamper-Resistance (1)
    Software system is never “tamper-resistant” to begin with
    → Is tampering detected? When?
    Access control has been used for existing databases
    Tampering is detected only with journals (logs)
    In distributed ledgers, relation among data is enforced
    ⇒ Simple tampering would cause contradictions
    Can detect tampering if a contradiction remains
    Cannot detect tampering if no contradiction remains
    World with Blockchain — and Blockchain Governance — 2018-07-10 – p.17/21

    View Slide

  18. On Tamper-Resistance (2)
    Platform Tampering Cost C Value V Condition C ≥ V Proactive
    Bitcoin (Basic) Mining Cost bitcoin Satisfied No
    Bitcoin (Applied) Depends Possibly Not Satisfied
    Ethereum Mining Cost Depends Possibly Not Satisfied No
    Private Ledgers N.D. but Small Depends Not Satisfied No?
    BBc-1 N.D. but Maximal Depends Satisfied Yes
    If condition C ≥ V is not satisfied, tampering can be noncontradictory and nondetectable
    Whether partial tampering (w/ contradiction) is proactively detected (with introspection) or not
    In any system, if a node is partially tampered, users may be malinformed
    Although contradictory transactions cannot be entered into a blockchain
    In general ledgers, if possibility of intrusion to (majority of) validators cannot be ignored,
    designers should consider proactive detection
    World with Blockchain — and Blockchain Governance — 2018-07-10 – p.18/21

    View Slide

  19. An Interesting Governance Issue
    “The problem” Bitcoin tries to answer and other blockchains to follow
    “How do I let nobody stop me from spending my own money?” (Freedom)
    Suppose some technology solves it, then
    “I” must be authenticated by my own (zero-knowledge proof of possession of private key)
    Everyone must be able to trace transfers (public record)
    Nobody may get the transferred money back (such policy)
    Have you heard of Mt.Gox, Coincheck or other cases of stolen coins?
    Once private key is illegally used, everyone knows where the stolen money is in the system,
    but nobody can get it back
    But the platform may choose to deny the incident by splitting a new history
    But then, does the platform take some juridical role?
    World with Blockchain — and Blockchain Governance — 2018-07-10 – p.19/21

    View Slide

  20. Cyber-Physical Society and Cybernetics
    Cybernetics began as understanding of animals in terms of communication
    and control, and is born to be physical anyways
    Society is acquiring new eyes, ears, arms and legs
    Ex. Wherever you are, they let you know that rain cloud is approaching to your town
    Ex. And a robotic system will bring in your laundry and fold them
    ⇒ Is the knowledge brought through the new eyes and ears correct?
    Is the control and its decision correct? Is the mission correct? Any bias?
    AI’s may be Byzantine nodes in the society as a network
    Byzantine = with arbitrary failures
    It may be meaningful to save and maintain records that even AI’s cannot alter
    World with Blockchain — and Blockchain Governance — 2018-07-10 – p.20/21

    View Slide

  21. Conclusions
    Any technology is an “answer” to a specific “question” in society
    We will need to question “what to question” first
    What do we expect for upcoming Cybernetically Organized (Cyborg) Society?
    It will inevitably be required to be dependable
    Issues are always socio-technical or techno-political
    World with Blockchain — and Blockchain Governance — 2018-07-10 – p.21/21

    View Slide