blockchains and adult education
TRANSCRIPT
Blockchains and Adult Education
Prof. John DomingueKnowledge Media InstituteThe Open UniversityUK
http://kmi.open.ac.uk/
http://blockchain.open.ac.uk/
BLOCKCHAINS IMPACT
Copyright http://dilbert.com/
Blockchain
3
WorldEconomicForumSurveyProjectsBlockchain‘TippingPoint’by2023
Santander:Blockchain TechCanSaveBanks$20BillionaYear
Bletchley:blockchainasaserviceinAzure
Everledgerwww.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?
Ablockchain isapermissionless
distributeddatabase,basedonthebitcoin
protocolthatmaintainsa
continuouslygrowinglistoftransactional
datarecordshardenedagainsttamperingand
revision,evenbyoperatorsofthedata
store'snodes.
Theinitialandmostwidelyknown
applicationoftheblockchain technologyisthepublicledgeroftransactionsforbitcoinandtheinspirationofsimilardistributedledgersknownas
altchains.
Eachblockchain recordisenforced
cryptographicallyandhostedonmachines
workingasadatastore
Source:Wikipedia
Cryptographic Hash Function
https://en.wikipedia.org/wiki/Cryptographic_hash_function
Blockchain is a Linked List (1/2)
Ablockchaincanbethoughtofasalinkedlistoftransactionsthatisbuiltwithhashpointersinsteadofpointers
Source:Bitcoin andCryptocurrency Technologies- ArvindNarayanan,JosephBonneau, EdwardFelten,AndrewMiller, StevenGoldfeder
Peer to Peer Network
http://www.terndrup.net/2015/10/27/Building-a-P2P-Peer-Client-with-Node-js/
Who Next?Addeveryonehasacompletecopyofthedata
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
Blockchain is a Linked List (2/2)
Ablockchain actuallycontainstwodifferenthash structures.Thefirstisahashchainof
blocks thatlinks thedifferentblocks tooneanother.
Thesecond isinternaltoeachblockandisaMerkle Treeof
transactionswithintheblocks.
This allowsforefficientlyverifiableproofs thata
transactionwasincluded inablock.
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:MarcEisenstadt ‘WhatisthegeniusbehindBitcoin’
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:MarcEisenstadt ‘WhatisthegeniusbehindBitcoin’
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 isacryptocurrencyplatformandTuring-completeprogrammingframeworkintendedtoallowanetworkofpeerstoadministertheirownstateful user-createdsmartcontractsintheabsenceofcentralauthority.
Itfeaturesablockchain-basedvirtualmachinethatsecurelyrecordsandincentivizesthevalidationoftransactions,i.e.codeexecutions,madethroughacryptocurrencycalledether.
Ethereum takestheprimarydevelopmentsusedbyBitTorrent andBitcoin,thepeertopeernetworkandtheblockchain,andgeneralizestheminordertoallowdeveloperstousethesetechnologiesforanypurpose.
Source:Wikipedia
Ethereum Blockchain Platform
Ethereum Blockchain Platform
Ethereum isa100%opensourcesoftwareplatformtobuilddistributed,decentralizedapplications
Ethereum is100%peertopeer,censorship-proofandcorruption-proof.
Ethereumcanbeusedtobuildanything:Assetissuance,crowdfunding,domainregistration,titleregistration,predictionmarkets,internetofthings,voting,educationalcertificateissuingsystems,hundredsofapplications
Source:Ethereum slides- StephanTual andEthereum in40minites byVitalik Buterin
Ethereum Virtual Machine
Sources:Ethereum DevelopmentTutorial
TheEthereum VirtualMachinecanbethoughtofasalargedecentralizedcomputercontainingmillionsofobjects,called"accounts",whichhavetheabilitytomaintainaninternaldatabase,executecodeandtalktoeachother.Thereare2typesofAccounts:
Externallyownedaccount(EOA):anaccountcontrolledbyaprivatekeythathastheabilitytosendetherandmessagesfromit.
‘Smart’Contract:anaccountthathasitsowncode,andiscontrolledbycode.
AnyusercantriggeranactionbysendingatransactionfromanEOA,settingEthereum's wheelsinmotion.
Ifthedestinationof thetransactionisanotherEOA,thenthetransactionmaytransfersomeetherbutotherwisedoesnothing
However, ifthedestination isa‘Smart’Contract,thenthecontractinturnactivates,andautomaticallyrunsitscode.
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:Devcon2slides– Ethereumin25MinutesbyVitalik Buterin
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:Devcon2slides– Ethereumin25MinutesbyVitalik Buterin
Gas
• Halting problem– Cannot tell whether or not a program will run
infinitely • Solution: charge fee per computational
step (“gas”)
Source:Devcon2slides– Ethereumin25MinutesbyVitalik Buterin
What are Ethereum Contracts?‘Smart’contractsarecomputerprotocolsthatfacilitate,verify,orenforcethenegotiationorperformanceofacontract.
‘Smart’contractscanbepartiallyorfullyself-executing,self-enforcing,orboth.
SmartcontractsinEthereumhavetheabilitytoread/writetotheirowninternalstorage,readthestorageofthereceivedmessage,andsendmessagestoothercontracts,triggeringtheirexecutioninturn
Sources:WikipediaandEthereum Development TutorialandEthereum - Introduction toSmartContracts
Contracts in Ethereum
Maintainadatastorerepresenting
somethingwhichisusefultoeitherothercontractsortotheoutsideworld
Serveasasortofexternallyowned
accountwithamorecomplicatedaccess
policy
Manageanongoingcontractor
relationshipbetweenmultipleusers
Providefunctionstoothercontracts;
essentially servingasasoftwarelibrary.
ContractsinEthereum generallyserve4purposes:
source: Richard GendalBrown “ASimpleModelforSmartContracts”http://gendal.me/2015/02/10/a-simple-model-for-smart-contracts/
DApps
Source:Ethereum - StephanTual
AĐapp isadecentralised applicationwhichservessomespecificpurpose toitsusers,butwhichhastheimportantproperty thattheapplicationitselfdoesnotdependonanyspecificpartyexisting.
Ratherthanservingasafront-end forsellingorprovidingaspecificparty'sservices,aĐapp isatoolforpeopleandorganizationsondifferent sidesofaninteractionusetocometogetherwithoutanycentralizedintermediary.
ADapp consistsoftwoparts:afrontend, writteninHTMLorQML,andabackend(thinkofitasthe‘database’foryourfrontend).
DBrowsers
ItisanenduserinterfaceontotheEthereumblockchain.
ADBrowser ishowuserswillfindandinteractwithDApps
‘Mist’isthenameoftheEthereumDBrowser.
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/
BLOCKCHAINS AND HIGHER EDUCATION
Copyright http://dilbert.com/
MSc Certificates on Blockchainhttp://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 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
Demosofmoviesavailableat:http://blockchain.open.ac.uk/
Certification
CourseContract
Functions:
Storage:
enrol
unenrol
getStudents
studentsPaid [address=0.6,address=0….]students[address,address,address]
CourseAdministrationViewStudentView
Enrol for6ETH!
yourEthereumaddress
passwordtoprivatekey
Signing this transactionwill transfer6ETH+gas fromyouraccount.Estimatedgascostis0.02ETH.Maximumgascostisset to0.05ETH
Enrol
StudentEnrolmentPage
SignedTX
Unenrol Student
AdminEthereum address
Adminpasswordtoprivatekey
Signing this transactionwill transfer6ETH+gas fromcourseadminaccount.Estimatedgascost is0.02ETH.Maximumgascostis set to0.05ETH
Unenrol
CourseAdminPage
SignedTX
StudentList
(Listingstudents is afreetransaction)
CourseEnrolmentPage
SignedTX
StudentAddressArray
unenrolStudentAccount11
StudentAccount23
StudentAccount45
StudentAccount67
StudentAccount89
unenrol
unenrol
unenrol
unenrol
StudentAccount67
Course Smart Contract
JaneenrolsonanOpenLearn Course
JaneenrolsonanOpenLearn Course
Blockno:45566778
JaneenrolsonanOpenLearn Course
JaneenrolsonanOpenLearn Course
JaneenrolsonanOpenLearn Course
JaneenrolsonanOpenLearnCourse
JaneenrolsonanOpenLearn Course
JaneenrolsonanOpenLearn Course
Demosofmoviesavailableat:http://blockchain.open.ac.uk/
Peer Accreditation
Higher Education Disaggregation
Collaborations
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
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
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
blockchain.open.ac.uk