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Blockchains and
Adult Education
Prof. John Domingue
Knowledge Media Institute
The Open University
UK
http://kmi.open.ac.uk...
BLOCKCHAINS IMPACT
Copyright	 http://dilbert.com/
Blockchain
3
World	Economic	Forum	Survey	Projects	
Blockchain	‘Tipping	Point’	by	2023
Santander:	Blockchain Tech	Can	Save	...
Everledger
www.everledger.io
IBM: Device Democracy
http://www-935.ibm.com/services/multimedia/GBE03620USEN.pdf
Distributed Autonomous Organisations
BLOCKCHAIN ELEMENTS
Copyright	 http://dilbert.com/
Ledgers
What is a blockchain?
A	blockchain is	a	
permissionless
distributed	database,	
based	on	the	bitcoin	
protocol	that	
mainta...
Cryptographic Hash Function
https://en.wikipedia.org/wiki/Cryptographic_hash_function
Blockchain is a Linked List (1/2)
A	blockchain	can	be	thought	of	as	a	linked	list	of	transactions	
that	is	built	with	hash...
Peer to Peer Network
http://www.terndrup.net/2015/10/27/Building-a-P2P-Peer-Client-with-Node-js/
Who Next?Add	everyone	has...
Proof of Work
• Find x such that f(nonce + x) < t
(cryptographic hash)
"Hello,	world!0"	=>	
1312af178c253f84028d480a6adc1e...
Blockchain is a Linked List (2/2)
A	blockchain actually	contains	
two	different	hash	structures.	
The	first	is	a	hash	chai...
Proof of Work
• Hard to outpace the entire rest of the network… a 51% attack could
do it, but otherwise it is like buying ...
Proof of Work
As you go back in time, an attacker would have to outpace the network
for a longer amount of time to carry o...
BitCoin Mining
http://knkx.org/post/central-wash-home-nations-biggest-bitcoin-mine-more-coming
https://cointelegraph.com/news/the-inevitable-failure-of-proof-of-stake-blockchains-and-why-a-new-algorithm-is-needed
Ethereum Blockchain Platform
Ethereum is	a	cryptocurrency	platform	and	Turing-complete	programming	
framework	intended	to	allow	a	network	of	peers	to	a...
Ethereum Blockchain Platform
Ethereum is	a	100%	open	source	software	platform	to	build	distributed,	
decentralized	applica...
Ethereum Virtual Machine
Sources:	Ethereum Development	Tutorial
The	Ethereum Virtual	Machine	can	be	thought	of	as	a	large	...
State vs History
• State = “current” information
– Account balances
– Nonces
– Contract code and contract storage
• Histor...
State
• State consists of key value mapping
addresses to account objects
• Every account object contains 4 pieces of
data:...
Gas
• Halting problem
– Cannot tell whether or not a program will run
infinitely
• Solution: charge fee per computational
...
What are Ethereum Contracts?
‘Smart’	contracts	are	computer	protocols	that	facilitate,	verify,	or	enforce	the	
negotiation...
Contracts in Ethereum
Maintain	a	data	store	
representing	
something	which	is	
useful	to	either	other	
contracts	or	to	the...
DApps
Source:	Ethereum - Stephan	Tual
A	Đapp is	a	decentralised application	which	serves	some	
specific	purpose	 to	its	us...
DBrowsers
It	is	an	end	user	interface	onto	
the	Ethereum blockchain.
A	DBrowser is	how	users	will	find	
and	interact	with	...
Characteristics of Blockchain DApps
• Shared database
• Multiple writers
• Absence of trust
• Disintermediation
• Transact...
BLOCKCHAINS AND HIGHER
EDUCATION
Copyright	 http://dilbert.com/
MSc Certificates on Blockchain
http://digitalcurrency.unic.ac.cy/certificates
35
MIT
“For example, after taking an examination
to demonstrate his or her academic
proficiency level, an individual could direct...
Demos	of	movies	available	at:	http://blockchain.open.ac.uk/
Certification
Course	Contract
Functions:
Storage:
enrol
unenrol
getStudents
studentsPaid[address=0.6,	address=0….	]
students	[address,	a...
Jane	enrols	on	an	OpenLearn Course
Jane	enrols	on	an	OpenLearn Course
Block	no:	45566778
Jane	enrols	on	an	OpenLearn Course
Jane	enrols	on	an	OpenLearn Course
Jane	enrols	on	an	OpenLearn Course
Jane	enrols	on	an	OpenLearn	Course
Jane	enrols	on	an	OpenLearn Course
Jane	enrols	on	an	OpenLearn Course
Demos	of	movies	available	at:	http://blockchain.open.ac.uk/
Peer Accreditation
Higher Education Disaggregation
Collaborations
Collaborations/Dialogue
• APII
• Banking Standards Board
• Blockchain Limited
• Consensys
• Ethcore
• Fraunhofer
• Imperia...
Summary
• Blockchains seem to be a revolutionary new platform for
sharing data at scale in a trusted fashion
• Provides th...
Acknowledgements
• KMi@OU Implementation Team
– Michelle Bachler
– Kevin Quick
– Allan Third
– Chris Valentine
• Discussan...
blockchain.open.ac.uk
Blockchains and Adult Education
Blockchains and Adult Education
Blockchains and Adult Education
Blockchains and Adult Education
Blockchains and Adult Education
Blockchains and Adult Education
Blockchains and Adult Education
Blockchains and Adult Education
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Blockchains and Adult Education

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Presentation given at an Invited talk at Leicester University. Covers work we are doing at the Open University on applying blockchains/distributed ledgers in the adult educational space

Veröffentlicht in: Technologie

Blockchains and Adult Education

  1. 1. Blockchains and Adult Education Prof. John Domingue Knowledge Media Institute The Open University UK http://kmi.open.ac.uk/ http://blockchain.open.ac.uk/
  2. 2. BLOCKCHAINS IMPACT Copyright http://dilbert.com/
  3. 3. Blockchain 3 World Economic Forum Survey Projects Blockchain ‘Tipping Point’ by 2023 Santander: Blockchain Tech Can Save Banks $20 Billion a Year Bletchley: blockchain as a service in Azure
  4. 4. Everledger www.everledger.io
  5. 5. IBM: Device Democracy http://www-935.ibm.com/services/multimedia/GBE03620USEN.pdf
  6. 6. Distributed Autonomous Organisations
  7. 7. BLOCKCHAIN ELEMENTS Copyright http://dilbert.com/
  8. 8. Ledgers
  9. 9. What is a blockchain? A blockchain is a permissionless distributed database, based on the bitcoin protocol that maintains a continuously growing list of transactional data records hardened against tampering and revision, even by operators of the data store's nodes. The initial and most widely known application of the blockchain technology is the public ledger of transactions for bitcoin and the inspiration of similar distributed ledgers known as altchains. Each blockchain record is enforced cryptographically and hosted on machines working as a data store Source: Wikipedia
  10. 10. Cryptographic Hash Function https://en.wikipedia.org/wiki/Cryptographic_hash_function
  11. 11. Blockchain is a Linked List (1/2) A blockchain can be thought of as a linked list of transactions that is built with hash pointers instead of pointers Source: Bitcoin and Cryptocurrency Technologies - Arvind Narayanan, Joseph Bonneau, Edward Felten, Andrew Miller, Steven Goldfeder
  12. 12. Peer to Peer Network http://www.terndrup.net/2015/10/27/Building-a-P2P-Peer-Client-with-Node-js/ Who Next?Add everyone has a complete copy of the data
  13. 13. Proof of Work • Find x such that f(nonce + x) < t (cryptographic hash) "Hello, world!0" => 1312af178c253f84028d480a6adc1e25e81caa44c749ec81976192e2ec934c64 "Hello, world!1" => e9afc424b79e4f6ab42d99c81156d3a17228d6e1eef4139be78e948a9332a7d8 "Hello, world!2" => ae37343a357a8297591625e7134cbea22f5928be8ca2a32aa475cf05fd4266b7 ... "Hello, world!4248" => 6e110d98b388e77e9c6f042ac6b497cec46660deef75a55ebc7cfdf65cc0b965 "Hello, world!4249" => c004190b822f1669cac8dc37e761cb73652e7832fb814565702245cf26ebb9e6 "Hello, world!4250" => 0000c3af42fc31103f1fdc0151fa747ff87349a4714df7cc52ea464e12dcd4e9
  14. 14. Blockchain is a Linked List (2/2) A blockchain actually contains two different hash structures. The first is a hash chain of blocks that links the different blocks to one another. The second is internal to each block and is a Merkle Tree of transactions within the blocks. This allows for efficiently verifiable proofs that a transaction was included in a block.
  15. 15. Proof of Work • Hard to outpace the entire rest of the network… a 51% attack could do it, but otherwise it is like buying thousands of lottery tickets – doesn’t help you that much! Source: Marc Eisenstadt ‘What is the genius behind Bitcoin’
  16. 16. Proof of Work As you go back in time, an attacker would have to outpace the network for a longer amount of time to carry out a double spend attack, and replace a block. Source: Marc Eisenstadt ‘What is the genius behind Bitcoin’
  17. 17. BitCoin Mining http://knkx.org/post/central-wash-home-nations-biggest-bitcoin-mine-more-coming
  18. 18. https://cointelegraph.com/news/the-inevitable-failure-of-proof-of-stake-blockchains-and-why-a-new-algorithm-is-needed
  19. 19. Ethereum Blockchain Platform
  20. 20. Ethereum is a cryptocurrency platform and Turing-complete programming framework intended to allow a network of peers to administer their own stateful user-created smart contracts in the absence of central authority. It features a blockchain-based virtual machine that securely records and incentivizes the validation of transactions, i.e. code executions, made through a cryptocurrency called ether. Ethereum takes the primary developments used by BitTorrent and Bitcoin, the peer to peer network and the blockchain, and generalizes them in order to allow developers to use these technologies for any purpose. Source: Wikipedia Ethereum Blockchain Platform
  21. 21. Ethereum Blockchain Platform Ethereum is a 100% open source software platform to build distributed, decentralized applications Ethereum is 100% peer to peer, censorship-proof and corruption-proof. Ethereum can be used to build anything: Asset issuance, crowdfunding, domain registration, title registration, prediction markets, internet of things, voting, educational certificate issuing systems, hundreds of applications Source: Ethereum slides - Stephan Tual and Ethereum in 40 minites by Vitalik Buterin
  22. 22. Ethereum Virtual Machine Sources: Ethereum Development Tutorial The Ethereum Virtual Machine can be thought of as a large decentralized computer containing millions of objects, called "accounts", which have the ability to maintain an internal database, execute code and talk to each other. There are 2 types of Accounts: Externally owned account (EOA): an account controlled by a private key that has the ability to send ether and messages from it. ‘Smart’ Contract: an account that has its own code, and is controlled by code. Any user can trigger an action by sending a transaction from an EOA, setting Ethereum's wheels in motion. If the destination of the transaction is another EOA, then the transaction may transfer some ether but otherwise does nothing However, if the destination is a ‘Smart’ Contract, then the contract in turn activates, and automatically runs its code.
  23. 23. State vs History • State = “current” information – Account balances – Nonces – Contract code and contract storage • History = things that happened – Transactions – Receipts • Currently, all “full” nodes store state, some store history and some do not store history Source: Devcon2 slides – Ethereum in 25 Minutes by Vitalik Buterin
  24. 24. State • State consists of key value mapping addresses to account objects • Every account object contains 4 pieces of data: – Nonce – Balance – Code hash (code = empty string for private key-controlled accounts) – Storage tree root Source: Devcon2 slides – Ethereum in 25 Minutes by Vitalik Buterin
  25. 25. Gas • Halting problem – Cannot tell whether or not a program will run infinitely • Solution: charge fee per computational step (“gas”) Source: Devcon2 slides – Ethereum in 25 Minutes by Vitalik Buterin
  26. 26. What are Ethereum Contracts? ‘Smart’ contracts are computer protocols that facilitate, verify, or enforce the negotiation or performance of a contract. ‘Smart’ contracts can be partially or fully self-executing, self-enforcing, or both. Smart contracts in Ethereum have the ability to read/write to their own internal storage, read the storage of the received message, and send messages to other contracts, triggering their execution in turn Sources: Wikipedia and Ethereum Development Tutorial and Ethereum - Introduction to Smart Contracts
  27. 27. Contracts in Ethereum Maintain a data store representing something which is useful to either other contracts or to the outside world Serve as a sort of externally owned account with a more complicated access policy Manage an ongoing contract or relationship between multiple users Provide functions to other contracts; essentially serving as a software library. Contracts in Ethereum generally serve 4 purposes: source: Richard Gendal Brown “A Simple Model for Smart Contracts” http://gendal.me/2015/02/10/a-simple-model-for-smart-contracts/
  28. 28. DApps Source: Ethereum - Stephan Tual A Đapp is a decentralised application which serves some specific purpose to its users, but which has the important property that the application itself does not depend on any specific party existing. Rather than serving as a front-end for selling or providing a specific party's services, a Đapp is a tool for people and organizations on different sides of an interaction use to come together without any centralized intermediary. A Dapp consists of two parts: a frontend, written in HTML or QML, and a backend (think of it as the ‘database’ for your frontend).
  29. 29. DBrowsers It is an end user interface onto the Ethereum blockchain. A DBrowser is how users will find and interact with DApps ‘Mist’ is the name of the Ethereum DBrowser.
  30. 30. Characteristics of Blockchain DApps • Shared database • Multiple writers • Absence of trust • Disintermediation • Transaction interaction • Set rules • Validators • Asset backing http://www.multichain.com/blog/2015/11/avoiding-pointless-blockchain-project/
  31. 31. BLOCKCHAINS AND HIGHER EDUCATION Copyright http://dilbert.com/
  32. 32. MSc Certificates on Blockchain http://digitalcurrency.unic.ac.cy/certificates 35
  33. 33. MIT
  34. 34. “For example, after taking an examination to demonstrate his or her academic proficiency level, an individual could direct the testing organization to share the test results with one or more third-party evaluating organizations.” “As education paradigms evolve, technological innovation is expected to diversify the ways in which tests are designed and individuals are evaluated. With this diversification and the changes it brings about, different evaluating organizations may come to utilize individuals' test results in different ways, each in accordance with its own evaluation methods.” http://www.sony.net/SonyInfo/News/Press/201602/16-0222E/index.html
  35. 35. Demos of movies available at: http://blockchain.open.ac.uk/ Certification
  36. 36. Course Contract Functions: Storage: enrol unenrol getStudents studentsPaid[address=0.6, address=0…. ] students [address, address, address] Course Administration ViewStudent View Enrol for 6 ETH! your Ethereum address password to private key Signing this transaction will transfer 6 ETH + gas from your account. Estimated gas cost is 0.02 ETH. Maximum gas cost is set to 0.05 ETH Enrol Student Enrolment Page Signed TX Unenrol Student Admin Ethereum address Admin password to private key Signing this transaction will transfer 6 ETH + gas from course admin account. Estimated gas cost is 0.02 ETH. Maximum gas cost is set to 0.05 ETH Unenrol Course Admin Page Signed TX Student List (Listing students is a free transaction) Course Enrolment Page Signed TX Student Address Array unenrolStudent Account 11 Student Account 23 Student Account 45 Student Account 67 Student Account 89 unenrol unenrol unenrol unenrol Student Account 67 Course Smart Contract
  37. 37. Jane enrols on an OpenLearn Course
  38. 38. Jane enrols on an OpenLearn Course
  39. 39. Block no: 45566778 Jane enrols on an OpenLearn Course
  40. 40. Jane enrols on an OpenLearn Course
  41. 41. Jane enrols on an OpenLearn Course
  42. 42. Jane enrols on an OpenLearn Course
  43. 43. Jane enrols on an OpenLearn Course
  44. 44. Jane enrols on an OpenLearn Course
  45. 45. Demos of movies available at: http://blockchain.open.ac.uk/ Peer Accreditation
  46. 46. Higher Education Disaggregation
  47. 47. Collaborations
  48. 48. Collaborations/Dialogue • APII • Banking Standards Board • Blockchain Limited • Consensys • Ethcore • Fraunhofer • Imperial • Institute of the Future • Jisc • KPMG • MIT • Mozilla Open Badges (BadgeChain) • Southampton • UCL
  49. 49. Summary • Blockchains seem to be a revolutionary new platform for sharing data at scale in a trusted fashion • Provides the basis for global distributed computation • Interestingly combines – History – Rules – Value • Has many application areas related to the recording and transference of value – Includes Higher Education and training • Badges and certification • ePortfolios • Educational reputation centric currencies • Disaggregation
  50. 50. Acknowledgements • KMi@OU Implementation Team – Michelle Bachler – Kevin Quick – Allan Third – Chris Valentine • Discussants – Sören Auer, Fraunhofer – Adi Ben-Ari, Applied Blockchain – Carla Casilli, Mozilla Open Badges – Marc Eisenstadt, OU – Matthew English, Fraunhofer – Denis Gillet, EPFL – Hugh Halford-Thompson, Blockchain Tech Ltd – William Knottenbelt, Imperial College – Konstantin Kudryavtsev, Ethcore – Gary McKay, APII – Rebecca Migirov, Consensys – Titi Roman, Sintef – Philipp Schmidt, MIT Media Lab – Mike Sharples, OU – Elena Simperl, University of Southampton – Ashley Taylor, Consensys – Sergej Zerr, University of Southampton • Graphics – Harriett Cornish, OU
  51. 51. blockchain.open.ac.uk

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