Blockchain Introduction
- 2. Ayham Madi MSc - Computer Security The University of Manchester “Experienced in Back-end development and system architecture, currently working on implementing the Blockchain technology in scientific research. In 2016 he joined Gep-Technologies as a software engineer, and he worked on many projects for security and identification. In 2014 he finished a BA in computer science from the University of Jordan, He was a member one of the university ACM teams, he also developed an OCR mobile application for his final year project. After his graduation, he worked in different companies in Jordan as a software engineer, during that period he received an Oracle associate certificate in Java”
- 4. What’s a blockchain (The Trust Machine) • Invented in 2008 • A protocol to establish trust • An append only Immutable database • Transparent records A distributed ledger of digital asset
- 5. Distributed network • Self dependent Peers/nodes • No central server
- 6. Peers/Nodes • Hardware and software (smart contract) • Uses their computing power to run the network • Holds data (Mining) • Validate transactions
- 7. Smart contract • A program • Validation procedure • Executed on every node
- 8. Transactions/Records • Validated by every node (through a smart contract) • Stored into blocks • Chained with previous records • Verified using cryptography
- 9. Cryptography • Symmetric Encryption • Asymmetric Encryption • Signing transactions • Hashing functions • A fingerprint for data
- 10. Blockchains with access control • Private blockchain • Permissioned blockchains • Public blockchain • Permission-less blockchains • Consortium blockchains • Public - Permissioned
- 11. Consensus • Proof of …. • Work • State • Storage • …… • Practical Byzantine Fault Tolerance
- 12. Proof of Work
- 17. Practical Byzantine Fault Tolerance(PBFT)
- 18. Practical Byzantine Fault Tolerance
- 19. Practical Byzantine Fault Tolerance Attack at 9 am Attack at 10amAttack at 9 am Attack at 9 am
- 20. Practical Byzantine Fault Tolerance
- 21. Practical Byzantine Fault Tolerance
- 36. • Smart Contracts • Customizable network (Public, private or consortium) • Rewards for miners in public networks • Customizable consensus mechanism • PoW: • PoS: • Po-Storage …
- 37. • Developed by the Linux foundation • Private blockchain for business • No rewards for data holders (miners) • Trust is build upon (PBFT) Practical Byzantine Fault Tolerance • Smart contract (Chaincode)
- 38. • DLT • Private blocks • Smart contract in any language • consensus through • transaction validity • transaction uniqueness • Extra level of privacy
- 39. Science and research • An immutable scientific workflows • Data sharing • Research evaluation • Research funding
- 40. Banking and Economics • Secure exchange • Clear audit trail • Fast identity check
- 41. And many more sectors • Healthcare • Government public records • Cars licencing • Music rights • Industries
- 42. Challenges • The Time Taken To Reach a Consensus • Scalability • Implementation and Switching cost
- 43. Thank you
Editor's Notes
- #4: Why everyone wants blockchain?
- #5: The trust machine A protocol to create trust between peers Build upon an append only database that holds transactions Transparent can be proved to every one That forms a distributed ledger
- #6: Self dependent Peers/nodes Every node can use it resources and help run it Is a network with no central node/server that every one rely on
- #7: A node can be any computer that runs a certain software (smart contract) It uses it’s memory and computing power to validate and store transactions
- #8: A program act like a validation procedure Transactions are validated based on the desired rules runs on every node run and validate against a certain input No interference by any party It gives the answer to: Who can we trust?
- #10: Shared Key or formula Two keys one for encryption and the other for decryption Hash function for generating fingerprints of data
- #11: Controlling 1 who can verify data 2 who can read data Private blockchained network for privacy Public usage of the network where every node has to participate in holding and verifying the transactions, usually some kind of incentive is offered to the participants A consortium blockchained network Some nodes handle the verification of the transactions. Where all transactions are public to everyone.
- #12: Consensus happens when: All nodes agrees on what is true/valid All nodes proofs how truth is generated All nodes stores the same valid transaction
- #23: Let’s take a general look on what is happening in the network We have 6 nodes
- #24: The first transaction is stored, hashed and verified by everyone
- #25: Same story for the second transaction, but the hash generated here is based previous record If the second record is hashed alone it will generate a different hash
- #26: Third transaction …. Same story
- #27: Now here when things gets interesting … Node F is compromised ….. Some records were edited and alter The next records are changed as well ………
- #28: But Every node is watching! And Node F is not a trusted node any more ….. The bigger the network the more secure it becomes
- #29: Why is blockchain is important in terms of cybersecurity? Because of “Trust” and integrity.
- #30: Internet of Things makes everything connected, but everything is vulnerable, everything has bugs! Cars has 50 millions lines of code only God knows what is happening there! Firdges, smartphones …. Same story
- #31: If any node becomes busy for whatever reason! We don’t care …. All nodes are equal and there is no single node that serve everyone.
- #32: No server! No server failure! All server errors are eliminated!
- #33: If any node is infected, compromised or attacked it will never affect the network!
- #34: Integrity is the target! We have a lake of trust over the internet Blockchain is the trust machine of the internet!
- #35: Every transaction is stored, hashed and verified by every one!
- #36: Who creates the blockchain? Developers, people!! These 3 are the most famous blockchain platforms available
- #41: Donations
- #42: Who owns what? Who graduated from the medical school? Who made this Nike shoes, or this apple device? Who owns this intellectual property?
- #43: Nothing comes for free ….