This document provides an overview of blockchain technology. It discusses how blockchain can provide an alternative to centralized ledgers for storing transaction records. Key points made include: - Blockchain uses a distributed ledger that is shared across a network of nodes and updated through consensus, eliminating the need for a centralized authority. - Information stored on the blockchain is hashed and encrypted, providing security. New blocks are added through proof-of-work mining which involves solving computationally difficult puzzles and is incentivized with cryptocurrency rewards. - Ethereum is a popular platform for building decentralized applications on blockchain through the use of smart contracts, which allow for automated execution of agreements. - Potential use cases of blockchain include banking,

1. TECHNICAL SEMINAR ON
OVERVIEW OF
BLOCKCHAIN
By S.LALITHA PRASANNA

2. Why Blockchain ?
Transactions - Everything around is a Transaction
● Payment of Bills
● Purchasing Tickets for travel
● Ordering Food
● Online shopping
Transactions are stored in Ledgers!
But where are the ledgers stored?

3. Drawbacks of Centralized Authority maintaining the Ledgers:
● Security breach
● Service charges
● Manipulation
● Permissions
● Natural disasters
What could be possible alternative for centralized ledgers ?

4. What is Blockchain?
● It is the technology behind the bitcoin
● A chain of blocks!
Flashback of blockchain:
1991: Stuart Haber and W. Scott Stornetta cryptographically described secure
chain of blocks.
1992:Bayer, Haber and Stornetta incorporated Merkle trees to the design,
which improved its efficiency by allowing several documents to be collected
into one block.
2008:The first blockchain was conceptualised by an anonymous person or
group known as Satoshi Nakamoto in 2008.
2008-Till date????

5. OVERVIEW OF NODES IN BLOCKCHAIN
● Every Block is verified in the chain

6. FEATURES OF BLOCKCHAIN
● Decentralized/distributed network
● Hash Encryption
● Proof of work
● Incentives for validation

7. Decentralization/Distributed ledger
● Decentralization is the process of redistributing or dispersing
functions, powers, people or things away from a central location or
authority.
● Decentralization enables disintermediation (it cuts out the
middleman)
● Decentralization eliminates inefficiencies inherent to centralized
institutions.

8. Hashing in Blockchain
Imagine a chunk of data is stored in a blockchain, such as a string of
characters.
● The digital data is chopped, minced and encrypted in a series of
alphabets and digits. This is called Hashing.
● Hashing makes the data unrecognisable which provides authenticity
to the data stored as each block of data has a unique hashing and the
validation takes place by comparing the hash of a block with the
previous hash stored in the subsequent block

9. Proof of Work
Consensus is the process by which block gets added to the Blockchain
after being validated by nodes.
● Bitcoin miners who validate have to solve complex mathematical
puzzle to add a block to the blockchain.
● Proof-of-Work involves solving computationally expensive puzzle
which is to solve but easy to verify.
● Miners search for specific nonce which gives the desired hash
which is predetermined

10. Incentives for validation
● Every miner who successfully validates a block is paid the incentive
● The current income is 12.1 BTC($25,170/ Rs.16,20,088) approx
● Bitcoin incentives is the only way to generate new currency into the
system.
● By 2140, all 21 million bitcoins will be mined.

12. VARIOUS PLATFORMS TO BUILD AND DEPLOY D-APPS:

13. Ethereum:
● Ethereum is a technology platform for decentralization
● Ethereum enables the creation of decentralized apps or“dapps”
● Scope: Apps run on the whole of the Internet
● Combines blockchain technology + smart contracts (self-executing, self-
enforcing agreements)
● Ethereum blockchain enables automated consensus between parties of a
contract Decentralization On a large scale

14. Smart Contract:
A smart contract is an agreement whose execution is both automatic and enforceable.
• The actual “transaction” among parties is expressed through and independently
executed by computer code,no party can block it or otherwise tamper with.
• It constitutes legally binding rights and obligations of the involved parties.
Advantages:
• Parties are in consensus at all times as to the existence, nature and evolution of the
facts shared among them, which are governed by the program.
• Used to satisfy common contractual conditions
• lower transaction costs and risk, and eliminate the need for trusted intermediaries.

15. BLOCKCHAIN USE CASES:

16. Blockchain Banking use case:
● Blockchain can cut upto $20billion middle man costs per year.
● Hacking into banking ledgers becomes close to impossible.
● Faster bank payments.
Eg: Goldman sachs,Barclays.

17. Blockchain Voting use case:
● Elections require authentication of voters identity,secure records
keeping and trusted tiles.
● Blockchain is the medium for collecting ,tracking,counting votes
without voter fraud,lost records or foul-play.
● Increases voter count.

18. BLOCKCHAIN APPLICATIONS:
● Brooklyn microgrid
● Chitmonks
● Bitgive
● Shocard
● Skuchain
● stamp.io
And many more….

19. THANK YOU