class 3.txt

Is there any uses case where only digital signature is broadcasted across the network?


1) Database vs Digital Ledger
2) 4 major pillars of blockchain (Cryptography, Ledger, Consensus, P2P NETWORK)
3) Cryptography ---> symmetric, asymmetric, digital signatures, hashing
4) Consensus ---> POW, POS, PBFT 

  pow, pos ---> public

pow:
-----
all miners will compute to a complex math problem ---> nonce
random no of zeros to be prefixed to the actual hash --->
block reward + txn fee to the miner

pos:
----
32ETH ---> miner in min staking fee

staking fee: 32eth

validation fee/block ----> 00.05 eth

txn fee = reward

No of miners: (21 miners) ---> binance miners


validations times ----> 15 sec - 1 min



POET ( PROOF of elapsed TIme)
------------------------------

1. Intel corp ---> they have developed a new hardware (circuit) consensus

[m1, m2, m3, m4, m5] ----> banks for credit score lending use case (cibil)



blocks are created ??

[100 txn]

Round1 ---> m1 m2 m3 m4 m5 ---> random election --> m3 miner ---> [1 2 3 4 5] --> B1 --> sleep time for 500 ms

Round2 ---> m1 m2 m4 m5    ---> random election --> m2 miner ---> [6 7 8 9 10] --> B2 ---> sleep time for 500 ms (m2 will sign the block data)

Round3 ---> m1 m4 m5 m3    ---> random election --> m5 miner ---> [11 12 13]   --> B3 ---> sleep time

Round4 ---> m1 m4 m3 m2    ---> random election --> m1 miner ---> [21 22 25]    ---> B4 ---> sleep time

softwre cracks ---> manipultae the clocks in the machines ----> SGX ---> software guard extension


txn [ t1 ---> U1 (b1) , 100 usd, u2 (b2) ] -----> b1 ---> txn, hash of txn, [minig pool], ]

    [ t2 ---> U3 (b1), 210 usd , u4 (b3)]   ----> b1 ---> txn, (wrong hash),  ---> txn/block

    digital sign ---> atomiciy of txn + hash (data), data ---> 

    [b1 b2 b3 b4 b5]

    [b6] ----> txns  ---> digital sign ---> (pk6, pvt6) ---->  stop/invalidate the txn


Genesis block ----> previous hash is empty

{

 network name: banke DLT network
 participants: b1 b2 b3 b4 b5
 pub keys    : pk1 pk2 pk3 pk4 pk5
 ip adress   : 120, 121, 123, 124, 135

}

prev hash as empty ---> reqd details


node is a machine ----> any node at some of point oftime ---> miner/validtor/leader


entreprise blockhains:
-------------------------

ledger / onchain txns ---> ledger (hashes)

actual data ---> off chain databases

(casandra) ---> mutiple replicas among the nodes as off chain DB




func Blockchain interfacs {

 createBlock()
 ProposeBlock()
 ValidateBlock()
 AddBlock()

}


M1 ---> miner --> Invokes createBlock, ProposeBlock

M2, M3, M4, M5 ---> Invokes ValidateBlock, AddBlock


M5 ---> miner --> Invokes createBlock, ProposeBlock

M2, M3, M4, M1 ---> Invokes ValidateBlock, AddBlock



{

t1 --> 100 btc ---> 8pm ist 3rd march --> 1 btc txn fee ---> b2, b3, b4
 
t2 --> 1000 btc --> 8.30 pm ist 3rd march --> 10 btc fee ---> B1

}


D2C ---> btc/eth/sol ---> dex


b2b ---> fabric, r3 corda --->


Creation of Blockchain network: (identifying participants)
--------------------------------

1. Creation of nodes/peers
2. Submission of transactions to the network
3. Consensus
4. Ledger


New Node Onboarding:
--------------------




Define rules only if all other banks confirm Yes (bank5)
 
if proposal recvd AND (BANK1, BANK2, BANK3, BANK4) ---> Bank5
                  3 out of 4 banks
                  OR ('Bank1', Bank4)



type nodeOnboarding interface {

  requestNetwork()
  getGenesis()
  successValidation()
  RequestforPreviosu()
  SyncBlock()

}




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

https://scrypt.io/
https://bitcoin.org/bitcoin.pdf


Genesis block:
---------------

{
  Supply of bitcoins : 21M
  Network            : Bitcoin core
  Network Id         : 12345
  Factor of Block reward : 0.5
  Difficulty Rate    : 2016
}     

21M

2009 -- 2023 ----> 19M are in circulation

to mine out entire 21M bitcoin -----> ~ 2140 Year


2009 ---> 2013 ----> Minng of single block ----> 50 BTC

2013 ----> 2017 ---> 25 btc

2018 ---- 2022 ----> 12.5 btc

2023 --- 2027 ----> 6.25 btc

2028 - 2032 ----> 3.175 btc


2140 ----> mine out all btc




for every block both block fee and txn fee is givenout to miners ---


0-2016 ----> {1,2,15,21,99900} linear


(exponential change in nonce) 2017-4032 --> {exponential change in nonce}  {2100000, 22, 23, ----- 50M}


(exponential change) 4032 - 6048 ----> (100M,,,, 1B) ---> 2040 ---->


Wallet address generation:
----------------------------

 everything is thru cryptgraphy in blockchains

1. create random public and private key pairs
2. comput sha256 hash(public,private)  ---> random value
3. comput RIPEMD160 hash(random value) ---> wallet address (bitcoin)


Multisignature wallets:  (Uniswap)
---------------------------------

1. account1 ---->867jljkhljhlkjhlkj (diff private and public key pairs)
2. account2 ---->9870987hkgjhgljhk  (diff private and public key pairs)

multiple wallets ---> 


pattern based attacks that can happen for blockchains ---> wallet1 ---> account1 ---> 4 yrs



Random words generated -----> friend stage spoon embrace bleak weird ignore cool stool elite guilt fatal



Exodus:
----------

1. https://downloads.exodus.com/releases/exodus-linux-x64-23.1.2.deb
2. Click on the download file, click show in folder
3. select the file, right click and goto permissions and select "Read and write" options, close
4. goto terminal
5. sudo dpkg -i exodus-linux-x64-23.1.2.deb