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![Ethereum Solidity – Token Contract
pragma solidity ^0.4.8;
contract MyToken {
...
event Transfer(
address indexed from,
address indexed to,
uint256 value);
/* Initializes contract with initial supply tokens */
function MyToken(
uint256 initialSupply,
string tokenName,
uint8 decimalUnits,
string tokenSymbol ) {
balanceOf[msg.sender] = initialSupply;
...](https://image.slidesharecdn.com/20171025blockchainiotnight-171025100757/85/Blockchain-IoT-Night-25th-Oct-2017-54-320.jpg)
Uploaded byLothar Wieske
Blockchain IoT Night / 25th Oct 2017
This document provides an overview of key blockchain and distributed ledger concepts including Bitcoin, Ethereum, Hyperledger, smart contracts, and related technologies like IoT and AI. It discusses the blockchain layers of immutability, authorization, and consensus for Bitcoin and Ethereum. It also summarizes the consensus approaches of proof of work, proof of stake, and PBFT used by different platforms.
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Blockchain IoT Night / 25th Oct 2017
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- 3. SMAC ... Augmented Reality Blockchain Internet ofThings ... ... Artificial Intelligence Cognitive Services Deep Learning ... Business >>> Customer Pipeline >>> Platform https://www.flickr.com/photos/n28307/11724219854/
- 5. Rise of DigitalPlatforms Over The Last 10 Years Oil Barrons Stepped Down - Silicon Kids Moved Up https://github.com/lwieske/digital-pipelines2platforms
- 6. At current churnrate, 75% of the S&P 500 will be replaced by 2027. https://www.innosight.com/insight/corporate-longevity-turbulence-ahead-for-large-organizations/ https://www.flickr.com/photos/justinwkern/6328287672/
- 7. Bretton Woods 1944 Nixon Shock 1971 LehmanCollapse 2008 All About The Money
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- 11. Transactions • are Multi-Input/Multi-Output. •consume Input All-or-Nothing. Bitcoin Blockchain LedgerJournalTransaction Blockchain
- 12. UTXO = UnspentTransaction Outputs As accounts have an all-or-nothing behaviour, the Bitcoin blockchain does not store the Ledger. It just keeps a list of UTXOs as pointers into the journal to keep all information. Bitcoin Blockchain LedgerJournalTransaction Blockchain
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- 15. HashPrevBlock is theSHA256 hash of the previous block. • Immutes all the historical blocks. MerkleRoot is the merkle root over the transaction list. • Immutes the current transaction list. HashPrevBlock MerkleRoot ................................ ................................ Block Header Bitcoin Blockchain - Immultability
- 16. HashPrevBlock MerkleRoot ................................... ................ Block Header BitcoinBlockchain - Immultability
- 17. A merkle treein general hashes elements in a list (leaves) and paires and hashes results until a merkle root remains. A merkle tree gives granularity in transaction validation; lite clients can validate entire blocks, transaction groups, or just single transactions with partial merkle branches only. #1 #2 #3 #4 #5 #6 #7 #8 78#56#34#12 #1234 #5678 #12345678 tx1 tx2 tx3 tx4 tx5 tx6 tx7 tx8 Bitcoin Blockchain - Immultability
- 18. https://www.flickr.com/photos/1ffischer/13925891289/ https://www.flickr.com/photos/cogdog/2568019743/ Authorization –Elliptic Curve Signatures secp256k1
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- 21. secp256k1 % openssl ecparam-param_enc explicit -text -noout -name secp256k1 Field Type: prime-field Prime: 00:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff: ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:fe:ff: ff:fc:2f A: 0 B: 7 (0x7) Generator (uncompressed): 04:79:be:66:7e:f9:dc:bb:ac:55:a0:62:95:ce:87: 0b:07:02:9b:fc:db:2d:ce:28:d9:59:f2:81:5b:16: f8:17:98:48:3a:da:77:26:a3:c4:65:5d:a4:fb:fc: 0e:11:08:a8:fd:17:b4:48:a6:85:54:19:9c:47:d0: 8f:fb:10:d4:b8 Order: 00:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff: ff:fe:ba:ae:dc:e6:af:48:a0:3b:bf:d2:5e:8c:d0: 36:41:41 Cofactor: 1 (0x1) Bitcoin Blockchain - Authorization
- 22. Bitcoin Blockchain -Authorization Bitcoin Curve over a very small prime number - ist GF(43). Private Key is an arbitrary number between zero and the order of the Abelian Group. Public Key results from repeated (#=Private Key) addition of the Generator to itself. ECDSA starts with that construction ... https://github.com/lwieske/blocktech-ecdsa/blob/master/ecdsa.ipynb
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- 24. Byzantine Agreement (single sourcehas an initial value) Agreement: All non-faulty processes must agree on the same value. Consensus Problem (all processes have an initial value) Agreement: All non-faulty processes must agree on the same (single) value. These problems are equivalent to one another! Bitcoin Blockchain - Consensus
- 25. FLP 1985 Impossibility ofDistributed Consensus with One FaultyProcess Fischer & Lynch & Paterson, JACM 1985 The consensus problem involves an asynchronous system of processes, some of which may beunreliable. The problem is for the reliable processes to agree on a binary value. In this paper, it is shown that every protocol for this problem has the possibility of nontermination, even with only one faulty process. By way of contrast, solutions are known for the synchronous case, the “Byzantine Generals”problem. Bitcoin Blockchain - Consensus
- 26. PBFT 1999 Practical ByzantineFault Tolerance Castro & Liskov, OSDI 1999 This paper presents a new, practical algorithm for state machine replication that tolerates Byzantine faults. The algorithm offers both liveness and safetyprovided at most out of a total of replicas are simultaneously faulty. The algorithm works in asynchronous systems like the Internet and it incorporates important optimizations that enable it to perform efficiently Bitcoin Blockchain - Consensus
- 27. Nakamoto Consensus 2008 Bitcoin:A Peer-to-Peer Electronic Cash System Satoshi Nakamoto, 2008 ... The network timestamps transactions by hashing them into an ongoing chain of hash-based proof-of-work, forming a record that cannot be changed without redoing the proof-of-work. The longest chain not only serves as proof ... that it came from the largest pool of CPU power. As long as a majority of CPU power is controlled by nodes that are not cooperating to attack the network, they'll generate the longest chain and outpace attackers. Bitcoin Blockchain - Consensus
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- 29. Difficulty demands leadingzeros in the block header hash. Nonce has to be guessed to achieve that. This guessing is compute intensiv, so it is a proof of work. Difficulty Nonce ................................ ................................ Block Header Bitcoin Blockchain - Consensus
- 30. Sometimes several minerscome with competing new blocks. There are rules to direct the race towards the longest chain. Finally, proof of work inhibits double spending of (U)TXOs. Difficulty Nonce ................................ ................................ Block Header Bitcoin Blockchain - Consensus
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- 35. Ethereum has NormalAccounts and Contract Accounts Bitcoin Blockchain LedgerJournal Blockchain
- 36. Normal Accounts andContract Accounts both have balances. Bitcoin Blockchain LedgerJournal Blockchain
- 37. Normal Accounts balancesare for currency transfer. Partial Spending. (They are not UTXOs.) Bitcoin Blockchain LedgerJournal Blockchain
- 38. Contract Accounts balancesare consumed for contract execution. Bitcoin Blockchain LedgerJournal Blockchain
- 39. Contract Accounts inaddition link to the contract code and state of execution. Bitcoin Blockchain LedgerJournal Blockchain
- 40.
- 41. Immutability merkle tree overthe transaction list hash over uncles list Patricia tries Ethereum Blockchain
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- 43. Consensus proof of workbased on ethash (memory hard) ghost protocol favoring heaviest chains (bitcoin favors longest chains) Ethereum Blockchain
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- 46. Hyperledger Fabric isa platform for distributed ledger solutions, underpinned by a modular architecture delivering high degrees of confidentiality, resiliency, flexibility and scalability. It is designed to support pluggable implementations of different components, and accommodate the complexity and intricacies that exist across the economic ecosystem. Hyperledger Fabric delivers a uniquely elastic and extensible architecture, distinguishing it from alternative blockchain solutions. Hyperledger
- 47. Immutability Authorization Consensus Immutability: SHA-256 Authorization: Public Key Infrastructure with RSA/ECC Keys Consensus: Practical ByzantineFault Tolerance (PBFT) Ethereum Blockchain
- 48. Nakamoto Consortium Network Structuredecentralized permissioned Scalability 1000s nodes 10s nodes Consensus Finality - + Throughput - + Latency - + Power Consumption - + Correctness Proof - + Nakamoto Consensus vs. Consortium Consensus Adapted from Marko Vukolic, IBM
- 49.
- 50. https://www.flickr.com/photos/hiltibold/6978014677/ A smart contractis a computerized transaction protocol that executes the terms of a contract. The general objectives of smart contract design are to satisfy common contractual conditions (such as payment terms, liens, confidentiality, and even enforcement), minimize exceptions both malicious and accidental, and minimize the need for trusted intermediaries. Related economic goals include lowering fraud loss, arbitration and enforcement costs, and other transaction costs Nick Szabo, 1994
- 51. Whisper (Network) Swarm (Storage) Engine (Compute) Ethereum Virtual Machine Ethereumallows users to create their own operations (not just predefined bitcoin transactions). This way, it serves as platform and protocol for decentralized blockchain applications – not only for cryptocurrencies. At the heart of Ethereum is the Ethereum Virtual Machine (EVM), an infrastructure (compute, network, storage) that executes code of arbitrary algorithmic complexity called Smart Contracts. Developers can create applications that run on the EVM using friendly programming languages modelled on existing languages like JavaScript and Python.
- 52. Whisper (Network) Swarm (Storage) Engine (Compute) Normal Accounts Contract AccountsGas ChainState EthereumVirtual Machine + Smart Contracts Ether is the fuel for operating the Ethereum platform. It is a payment to the machines executing the requested smart contract operations on the EVM. The total supply of ether and its rate of issuance was decided by the donations gathered on the 2014 presale. The results were roughly: 60 million ether created to contributors of the presale and 12 Million (20% of the above) were created to the development fund. 5 ethers are created every block (roughly 15-17 seconds) to the miner of the block and 2-3 ethers are sometimes sent to another miner if they were also able to find a solution but his block wasn't included (called uncle/aunt reward).
- 53. Whisper (Network) Swarm (Storage) Engine (Compute) Normal Accounts Contract AccountsGas ChainState FromSmart Contracts to Decentralized Applications
- 54. Ethereum Solidity –Token Contract pragma solidity ^0.4.8; contract MyToken { ... event Transfer( address indexed from, address indexed to, uint256 value); /* Initializes contract with initial supply tokens */ function MyToken( uint256 initialSupply, string tokenName, uint8 decimalUnits, string tokenSymbol ) { balanceOf[msg.sender] = initialSupply; ...
- 55. Ethereum Wallet –Deploy New Contract
- 56. Ethereum Wallet –Contract Source Code
- 57. Ethereum Wallet –Create Contract
- 58. Ethereum Wallet –Send Funds
- 59. Ethereum Wallet –Receiver Adds Token
- 60.
- 61. Internet of Things AutonomousObjects Programmable Value https://www.flickr.com/photos/carstenc/10266217656/
- 62.
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- 64. https://www.flickr.com/photos/32716504@N03/8380889887/ Blockchain Technology (BlockTech) can trackconnected devices, process transactions, coordinate devices, and enable autonomous behaviour.
- 65. Brooklyn Microgrid Brooklyn isknown the world over for things small-batch and local, like designer clogs, craft bourbon and artisanal sauerkraut. In a promising experiment in an affluent swath of the borough, dozens of solar-panel arrays spread across rowhouse rooftops are wired into a growing network. Called the Brooklyn Microgrid, the project is signing up residents and businesses to a virtual trading platform that will allow solar- energy producers to sell excess-electricity credits from their systems to buyers in the group, who may live as close as next door.
- 66. slock.it - TheUniversal Sharing Network: Rent, Sell or Share Anything With Slock.it, Airbnb apartments become fully automated, smart objects can be rented on demand and unused vehicles get a new lease on life.
- 67. set deposit pay deposit returndeposit set price receive payment lock / unlock
- 68.
- 69.
- 70.
- 71.
- 72. https://www.flickr.com/photos/intherough/3253349104/ Blockchains drive businessand technology. Bitcoin‘s Proof-of-Work scales to 1000s of nodes. Etherum plans to adopt Proof-of-Stake very soon. Hyperledger partitions into endorsing and validating nodes. Smart Contracts/Chaincodes enable programmable values. Blockchains transforms the Internet-of-Things into an Internet-of-Value.