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Blockchain

Blockchain#

Introduction#

Trade-offs#

  • Public vs Private
  • Security vs Performance

Terminologies#

  • Genesis
  • Consensus
    • Proof-of-Work
    • Proof-of-Stake
    • Proof of Byzantine Fault Tollerance
  • Black Node/Block
  • Orphan Block (Purple)
  • Immutable distributed Ledger
  • Double Spending
  • Node
    • Any computer that connects to the Bitcoin network is called a node
    • every mining computer, every computer that has a bitcoin wallet and by special sites that give blockchain monitor services
  • Full Node
    • Nodes that fully verify all of the rules of Bitcoin
    • Full nodes download every block and transaction and check them against Bitcoin's consensus rules
  • Merkle Tree
    • Hash of transaction in a block
  • Keys
    • Source
    • Private Key (64): Assiged to node on joining network
    • Public Key (34): same as above but can be publiced, same as bitcoin QR code
      • balances in wallet are fetched from bitcoin address, which is public key of the wallet

Components#

  • Transactions
    • commits changes to the blockchain
    • contains signature of owner of address
    • many transactions inside a block
  • Blocks
    • conatins an ordered bunch of transactions
      • timestamps the transactions, are immutable
    • each block references the previous block

Block#

  • Hash
  • Data
  • Previous Hash

Features#

  • Encryption of data
  • Proof-of-work
  • History
  • Decentralized Data
  • Trust in Data
  • No Intermediaries
  • Network Type
    • Public
    • Private
  • Authentication
    • peers signs the transaction with their private key

Applications#

  • Banking & Money Transfer
  • Healthcare
  • All types of document management
    • Land / Real State
      • Owner's Doc
      • Transfer Deeds
      • Land History
    • Certificates
      • Birth
      • Caste
      • Marriage
      • Death
    • Contracts
  • Governance
    • All the govt. data
  • Voting
    • Voter Registration
    • Voter Identification
    • Electronic Voting
  • Cloud Storage
  • Digital Twin
  • Energy management
  • Online Music
  • Retail Shops
  • Crowdfunding
    • Startups
    • Govt. & Contractor
  • Avoid Intermediaters
    • Advocate
    • Bank
    • Other 3rd Parties
  • Blockchain + AI
    • Decentralized AI platform

Facts#

  • data commited to ledger cann't be changed

Frameworks#

Source1: https://medium.com/hyperlegendary/6-blockchain-frameworks-to-build-enterprise-blockchain-how-to-choose-them-2b7d50ba275c
Source2: https://www.blockchain-council.org/blockchain/list-of-best-open-source-blockchain-platforms/

  • Hyperledger (active Consumer): https://github.com/hyperledger/composer/
  • Ethereum: https://github.com/ethereum
  • MultiChain: https://github.com/MultiChain , https://www.multichain.com
  • OpenBlockChain : https://github.com/openblockchain
  • Eris

Workflow#

  • genesis
  • few transactions by few peoples
  • transactions stored temporary in transaction pool
  • many miners try to solve for candidate block
    • candidate block is the next block going to be added to the blockchain
    • a block can store a limited amount of transactions (1MB, in Bitcoin Hard Cash 8MB, 500 transactions etc.)
    • they will take the all transaction data and create hash from that by making chnages in nonce
  • any one miner won the race
  • he will broadcast the hash/new to the network
  • rest of the miners will validate the calculated hash
    • there are some math like value of hash should be less than target
      • source: http://learnmeabitcoin.com/guide/blocks)
      • or a simple math for example, hash should start with 0000
  • if validations succeed, all the

FAQ#

  • how data changes reaches to the leader
  • how leader'd PoW are verified
  • where the new block will get added if one leader solved the problem
  • what is the mathematical problem to be solved
  • how many transactions in single block
  • when is new block created and why?
  • how creation/updation in doc will be validated, before audit?
  • how to avoid false data entry by doctors?
  • how to add real time data like, pulse, heartbit directly from device? include IoT?
  • who are PoW validators? Are the other miners?
  • who are ledger keepers? are they miners?

Multichain#

Installation#

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su (enter root password)

cd /tmp
wget https://www.multichain.com/download/multichain-1.0.5.tar.gz
tar -xvzf multichain-1.0.5.tar.gz
cd multichain-1.0.5
mv multichaind multichain-cli multichain-util /usr/local/bin (to make easily accessible on the command line)

exit (to return to your regular user)

Getting Started#

Nodes On Different Servers#

Node 1 Initial Setup on Server 1#

  • Run 

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    #Create chain1
multichain-util create chain1

  • Output 

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    MultiChain 1.0.5 Utilities (latest protocol 10011)

Blockchain parameter set was successfully generated.
You can edit it in /home/toran/node1/chain1/params.dat before running multichaind for the first time.

To generate blockchain please run "multichaind chain1 -daemon".

  • Run 

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    #Initialize Blockchain with genesis block
multichaind chain1 -daemon

  • Output 

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    MultiChain 1.0.5 Daemon (latest protocol 10011)

Starting up node...

Looking for genesis block...
Genesis block found

Other nodes can connect to this node using:
multichaind [email protected]:6725

Listening for API requests on port 6724 (local only - see rpcallowip setting)

Node ready.

Node 2 Connection with Node 1 on Server 2#

  • Run 

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    multichaind [email protected]:6725

# aws node
multichaind -datadir=/home/toran/node2 -port=10255 -rpcport=10254 [email protected]:6821 -daemon

  • Output

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    MultiChain 1.0.5 Daemon (latest protocol 10011)

Retrieving blockchain parameters from the seed node 192.168.1.100:6725 ...
Blockchain successfully initialized.

Please ask blockchain admin or user having activate permission to let you connect and/or transact:
multichain-cli chain1 grant 1UcDevL9XAeEeHu5qtjBqcdXTsLfELW3nHt5YR connect
multichain-cli chain1 grant 1UcDevL9XAeEeHu5qtjBqcdXTsLfELW3nHt5YR connect,send,receive

Back on Server 1#
  • Run
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    multichain-cli chain1 grant 1UcDevL9XAeEeHu5qtjBqcdXTsLfELW3nHt5YR connect
Back on Server 2#
  • Run
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    #Now try reconnecting again
multichaind chain1 -daemon
Delete a Chain#
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#Stop it running
multichain-cli chain1 stop

#Delete its directory
sudo rm -r ~/.multichain/chain1

Nodes On Same Server#

Node 1 Initial Setup#

  • Run 

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    mkdir /home/toran/node1
multichain-util create chain1 -datadir=/home/toran/node1

  • Output 

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    MultiChain 1.0.5 Utilities (latest protocol 10011)

Blockchain parameter set was successfully generated.
You can edit it in /home/toran/node1/chain1/params.dat before running multichaind for the first time.

To generate blockchain please run "multichaind chain1 -daemon".

  • Run

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    multichaind chain1 -daemon -datadir=/home/toran/node1

  • Output 

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    MultiChain 1.0.5 Daemon (latest protocol 10011)

Starting up node...

Looking for genesis block...
Genesis block found

Other nodes can connect to this node using:
multichaind [email protected]:6725

Listening for API requests on port 6724 (local only - see rpcallowip setting)

Node ready.

Node 2 Connection with Node 1#

Syntax: multichaind -datadir=<your_path_to_multichain2nd_directory> -port=10255 -rpcport=10254 chain0 -daemon

  • Run

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    mkdir /home/toran/node2
multichaind chain1@<chain1-ip>:<chain1-port> -datadir=/home/toran/node2

  • Output

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    MultiChain 1.0.5 Daemon (latest protocol 10011)

Retrieving blockchain parameters from the seed node 192.168.1.100:6725 ...
Blockchain successfully initialized.

Please ask blockchain admin or user having activate permission to let you connect and/or transact:
multichain-cli chain1 grant 1UcDevL9XAeEeHu5qtjBqcdXTsLfELW3nHt5YR connect
multichain-cli chain1 grant 1UcDevL9XAeEeHu5qtjBqcdXTsLfELW3nHt5YR connect,send,receive

  • Run

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    multichain-cli chain1 -datadir=/home/toran/node1 grant 1UcDevL9XAeEeHu5qtjBqcdXTsLfELW3nHt5YR connect

Commands in Interactive Mode

sudo mkdir ~/.multichain/chain1

multichain-cli chain1 -datadir=/home/toran/node1

multichaind -datadir=/home/toran/node2 -port=10255 -rpcport=10254 [email protected]:6821 -daemon

multichain-cli mychain -datadir=/home/toran/node2

  • allow port range in aws instance, like 1000-9999 in all multichain nodes aws instace
  • while running the node chain@ip:port, this port is used in cli
  • while API port is used in python/code

multichain-cli -datadir=/home/ubuntu/toran-aws block-chain create stream "scheme" true

IP: vin-new: 34.255.8.211 tom: 13.232.130.184 my: 13.232.100.99