class 10.txt

Reference links:
----------------

https://github.com/blockchaintraining90/batch4

https://bitcoinsv.com/scrypt/
https://bitcoin.org/bitcoin.pdf

https://ethereum.org/en/
https://www.openzeppelin.com/
https://ethereum.github.io/yellowpaper/paper.pdf
https://www.tutorialspoint.com/solidity/index.htm
https://docs.ethers.org/v5/
https://web3js.readthedocs.io/en/v1.8.1/


https://hyperledger-fabric.readthedocs.io/en/release-2.5/
https://www.youtube.com/c/Hyperledger
https://github.com/hyperledger/fabric-samples


https://docs.r3.com/

https://www.tutorialspoint.com/nodejs/index.htm





makes use of promises to handle async calls




1. getUsername
2. CreateTxn
3. Read from DB

req --> 1
createTxn --> 2
Read from DB --> 3

1....> done...> promose is resolved
 ..2...(txn and not submited)...> start
  ....1....> compltes
   ....2.... --> create txn...> ...promise is rejected
    ....3....> read DB (http, usern pwd) ... completed/failed
     ...3....> done


Chaincodes ----> shoudnt be too complex and holds only business logic

servers / handling multiple req ---> client/server applications (restful services)

clinets ---> restful servcies ---> fabric-network --> chaincodes/smartcontracts

write a program to create file and store identity details:
---------------------------------------------------------

var fs = require('fs')

fs.createfile(home/ubuntu/simplielear/hyperledger/fabric/identity/cert)
fs.wrirefile(__dirname + "jkjhfkj")
delete file
apped file

REST APIs:
---------

1. GET -- read from server
2. PUT -- write data into server
3. DELETE -- wipe data from server
4. POST   -- write/override existing data on server

 
express framework it proves easy way of managaing these methods

var express = require('express')
var app     = express();
var port    = 5000;
app.get('/',function (request, response) {
  response.send('Hello World')
})
var server = app.listen(port, function() {
 var host = server.address().address
 var port = server.addresss().port
 console.log("server running on port")
});


Corda:
-------

Flows: Represent entire work flow for a transaction to complete

usra - usrb ---> 100 USD


1. Initiate a txn from usra
2. Debit funds from usra (smart contract)
3. transfer funds from usra to usrb (smart contract)
4. credit funds to usrb (smart contract)
5. terminate the txn

Validity consensus:
-------------------

usera - current balance --> 100

usera --> 100 ---> userb

txn --- { txnid, digcert, pubK, hash)

smartc func validate txn (txnid, digcert, publickey, hash)

it validates the digital sign/certificates



usera ---> 100 ---> userc


Uniqueness consensus:
---------------------

1) notary -----> which has visibilty on all ledgers of the network

notary: (1,2,3,4,5,6,7,8,9) ---- central componentin corda
------

 2 txn from same user with diff ledger ---> invalid 1 txn

ledger1 ---(a,b) ---(1,2,3)

ledger2 ---(a,c) ---(4,5,6)

ledger3 ----(b,c) --- (7,8,9)


type BlockStruct{
   Header: string[]
   Body:
     txn string []
     hash string []
}


type TxnStruct {
      TxnPrevHash []
      TxnCurrHash []
}



txn1 ----- node1 to node2  

 [ node1 --- 100.201.161.141
   node2 --- 100.201.161.151
   node  --- 100.202.143.123
 ]


Reference links:
----------------

https://github.com/blockchaintraining90/batch4


Blockchain Use cases:
---------------------
       
1. Finance     --- Initial Public Offering
2. Insurance   --- Insurance (claim/reinsurance/reinstatement)
3. Loyalty     --- Loyalty rewards


IPO:
----

Company ABC wants to raise funds and goes to public

1. Due dilegence and auditing from Big4 audit firms to ABC --> DB
2. ABC will issue X crore amount (100 Crore), share value of 100/unit --> DB
3. ABC will approach Security Boards (governing authorities) -- (logic of allotment)
4. Log this entru details as valid in their DB
5. ABC company can contact channels/brokers (zerodha/groww/upi) etc
6. channels/brokers can enroll/opt/bid for the shares
7. Mandate wil be created per customer and amount gets locked/debited from account
8. Based on the subsrciption the share are distributed to all customers (oversubscribed/under subscribed)
9. Refund/partial refund
10. share allocation/allotment


100 units of ABC, 100 * 100 = 10000 INR
oversubscribed

100 units ---> 75 units are allocated and rest 25 units will be refunded

painful process --> Long and time taking, reconcilation of data at every step


Blockchain platform:
--------------------

PCI/DSS standards ---> advicable
Gas fee/txn fee   ---> eth/polygon

Hyperledger Fabric ---> 



Configtx.yaml:
--------------

Orgs:
----
1. ABC          - Peer0.org1
2. Audit Firm   - Pee0.org2
3. Broker app   - Peer0.org3
4. Security     - peer0.org4


smartcontract:
-------------

1. creation of request
2. allocation of shares ---> outside blockchain (SEBI)
3. refund details
4. txn status

allocation smartcontract -- blockchain

Ordering service:
-----------------

1. Security Board -- order0.order

Consensus: etcdraft

ledger: /var/production/hyperledger/fabric/ledger/IPO/details

 txn1 {user1,userid,shares req:100,amt blocked: 10000, date of req: 12 dec 22} ----> Invoke chaincode function - creation of request --org4 -- 12th dec
 txn1 {user1,userid,shares req:100,shares allocated 75,refund sahres:25} ---> allocation 19th dec
 txn1 {user1,userid,shares req:100,shares allocated 75,refund sahres:25,ref amt 2500,refund date: 19 dec 22} --- refund function
 txn1 --valid and refund completed

MSP:
----
org1MSP
 cert
 pubK
 priK

channel: IPOChannel

Endorsement POlicy:
-------------------

(('ORG1MSP' OR 'ORG3MSP') AND ('ORG4MSP'))

Chaincode: ipoallocation_chaincode

 location: /var/production/chaincode/ipo/ipoallocation.tar.gz


Benefits:
---------
1. near realtime refunds
2. reconcilation process reduced
3. better turn around times


If we implement ERC20 for this use case: Tokenization
----------------------------------------

1. ABC -- 100 CRORE 
   100 CRORE - ERC20 -- 100 CRORE ERC20 TOKENS

 ERC20

 {
  token name -- ABC Token
  supply --- 100 crore
  ownership --- ABC
  date of cretion -- 12 dec
 }


75 units ---> diff serial numbers ---> (user1+custid+1 
      jagdish12345001 to jagdish12345075 )

proof of ownership:
 jagdush12345050 ---> call smart contract function ---> track ownership --- func (tokenserial, name)
    owner --- jagdish) 


Lolayty rewards:
----------------

jetairways ---> 15000 milepoints

airindia   ---> 20000 

indigo

xyz

DGCA ---> Civil aviation: jet,air,indigo xyz 
-------------------------

airindia  ----> 30000 , 35000 -----> 5000 mile balance



bank of india, bank of singapore, bank of taiwan, JPMC, ABC corp Ltd ---> Corda 

Corda -- java/kotlin
Fabric -- java/javascript/go
ETH/POLYGON -- solidity
Solana -- rust