class 8.txt

Agenda is to create truffle projc


prerequisites --- node v18, truffle, solidity compiler


Step1: Install node js version 18
--------

sudo apt install curl 
curl https://raw.githubusercontent.com/creationix/nvm/master/install.sh | bash 
source ~/.bashrc
nvm install 18

Step2:
--------
npm install -g truffle (or) sudo npm install -g truffle

Step3: crete workspace for project
------

mkdir MetaCoin
cd MetaCoin

Step4: truffle unbox for standard folder/project structure
-------

sudo truffle unbox metacoin or truffle unbox metacoin

Step5:
---------

truffle compile or sudo truffle compile





Public blockchains:
--------------------


 1. ledger access is visible for everyone
 2. identity are anonymus

Private blockchains:
-------------------- 

100 banks 


phase1:
-------

network1- 

10 banks are coming together to create a project called CreditLedger

 a--->b txn1 ---> securely so that others in network

 channels --> thru which diffefernet business entities can create and exchange info thru the


a--->b 10 txn, 2 more private txn

ledger:
1. data attrbutes
2. 
.
.
.
10. data ttributes

11. private [data attiubutes]
12. private [data attiubutes]


other banks will store hash of these private data:

11. hash of the private data
12. hash of the private data

potential gain that TAT for settlements and manual dispute is decreased by 20%

2 more banks wishes to join

config file:
-------------

seed nodes -

1 more bank wishes to drop off after 5 yrs


rest of banks ~ 100 / 150 ----> no visibility of the data/ledger access

txn1 -----> sbi to canara bank (sbi, canara) ---> validate
txn2 -----> sbi to karanta bank (sbi, karat) ---> validate


block1---->  2 txns 


policies:
-----------

 txn is being involved b/w bank A and bank B ----> it has to get approval from both banks ('bank A' AND 'bank B')

 failed -- bank B hasnt given


both options ---

1. we can store data (normal data fields)
2. we can store hash of the data (sensitive data)

type Transaction {

 userName public
 AccountNum public
 SSN        private
 MobNum     private 
} 









network2

 10 insurance wants to create InsureLedger ----> claim process

 these doesnt require any kind of transaction/gas/crypo fee ---> higher adoption



INdy:
----


User A -----> wallet ----> can generate and store multiple DID

 did1 ---> universirty degree (name, roll num, college, email) ----> func geneID (params) ---> unique id
 did2 ---> credit/financial enquire ----> (name, email, bank accnt, bank name) --> func geneID(params) --- unique id2


Orgs are building their own network:

 sawtooth --->  Intel, Fujitsu
 Iroha    --->  IBM, accentur
 Indy     --->  DID use case 
 Fabric   ----> IBM

90% ----> Fabric


In Fabric terms, chaincode(permissioned) and smart contract(piblic) are same


network boot strap process:
-----------------------------

1. admin will create identities for all business entities (10 banks)
 
 bank 1 ----> Identity1 {bank name, bank url, bank ip address, bank port, bank public key, bank x509 certs)
 bank 2 ----> Identity2

Consensus: RAFT, POS, DPOS, Smart BFT, PBFT ----> used (Raft)

smart contract: node js, go, java, python(not advicible) ----> used (go/java)

api/sdk: java, node js, go --->   used ---> go/java


Identity Module:
-------------------

1. creates identity for business entities to be identifibale in the network

 bank 1 is onboarded
   
  {
    bak name
    bank ip 
    bank port
    bank x509 certificates
    bank public key
 }

idneity folder strucure  which is called MSP 




 Bidding/auction based financial platform:
-------------------------------------------

 SEBI/CENTRAL party

quote details ----> can only be sent/exchange b/w ----> bank a, sebi

 we can define policy at transaction or smart contract level:

  Ploicies : which requires approval/signature from bank A and SEBI



config:
-------


channel1 ----> bank A, SEBI



    

   if PVT TXN = 'channel1'

      {
         policy = 'bank A' and 'SEBI'
      }

  if NRML TXN 
    { 
         polic = 'bank A' OR 'bank B'
    }


 10 banks

  if my txn is validated from 6 out of 10 banks ( n out of m)

 I can consider this as valid txn

 


Membership, Blockchain (peer to peer network), Transaction, Chaincode

Peer roles: 
-----------

endorsement
commiting
anchor
leader