Blockchain technology is a decentralized digital ledger that can record transactions and virtually anything of value. It uses cryptography to allow transactions to be securely recorded and verified without a central authority. The blockchain is maintained by a network of computers running the blockchain protocol and software. New transactions are added to the ledger in groups called blocks, and nodes work together to confirm the validity of transactions using cryptography before they are added to the blockchain. Blockchain has applications in digital currencies like Bitcoin, smart contracts, supply chain management, digital identity, and more. It allows value to be exchanged in a secure, transparent and conflict-free way without intermediaries.

1. BLOCKCHAIN TECHNOLOGY
PREPARED BY KADARI SHIVRAJ

2. WHAT IS BLOCKCHAIN TECHNOLOGY?
• “The blockchain is an incorruptible digital ledger of economic
transactions that can be programmed to record not just financial
transactions but virtually everything of value.”
Don & Alex Tapscott, authors Blockchain Revolution (2016)
• It is a brainchild of a person or group of people known by the
pseudonym, Satoshi Nakamoto.
• It is a decentralized technology.

3. BLOCKCHAIN-A NETWORK OF NODES
• Node- Computer connected to the blockchain network using a
client that performs the task of validating and relaying transactions.
• A network of so-called computing “nodes” make up the blockchain.
• Every node is an “administrator” of the blockchain.

4. WHAT IS CRYPTOCURRENCY: 21ST-
CENTURY UNICORN – OR THE MONEY OF
THE FUTURE?• Basically, cryptocurrencies are entries about
token in decentralized consensus-databases.
• They are called CRYPTOcurrencies because the
consensus-keeping process is secured by
strong cryptography.
• Cryptocurrencies are built on cryptography.
They are not secured by people or by trust, but
by math.
• It is more probable that an asteroid falls on
your house than that a bitcoin address is
compromised.

5. BLOCKCHAIN-MINERS
• Confirmation is a critical concept in cryptocurrencies and only
miners can confirm transactions.
• They take transactions, stamp them as legit and spread them in
the network.
• After a transaction is confirmed by a miner, every node has to
add it to its database and then it becomes part of the
blockchain.
• For this job, the miners get rewarded with a token of the
cryptocurrency, for example with Bitcoins.

6. BLOCKCHAIN-BITCOIN
• Bitcoin is a worldwide cryptocurrency and digital payment system, invented
by an unknown programmer, or a group of programmers, under the
name Satoshi Nakamoto.
• Bitcoin is called the first decentralized digital currency.
• Satoshi Nakamoto created Bitcoin as a reward for miners for mining but
later on it became a medium of exchange.
• Bitcoins can only be created if miners solve a cryptographic puzzle.
• After finding a solution, a miner can build a block and add it to the
blockchain. This is called the Proof-of-Work. In Bitcoin, it is based on
the SHA 256 Hash algorithm.
• Bitcoin is called as “digital gold” and till date, the total value of the currency

7. BLOCKCHAIN- SHA 256 HASH ALGORITHM.
• A hash algorithm is a function that converts a data string into a
numeric string output of fixed length.
• SHA-2 (Secure Hash Algorithm 2) is a set of cryptographic hash
functions designed by the United States National Security
Agency (NSA).
• SHA-256 is one of the successor hash functions to SHA-1
(collectively referred to as SHA-2), and is one of the strongest
hash functions available.

8. BLOCKCHAIN- SMART CONTRACTS: THE
BLOCKCHAIN TECHNOLOGY THAT WILL REPLACE
LAWYERS
• Smart contracts helps to exchange money, property, shares, or
anything of value in a transparent, conflict-free way while avoiding
the services of a middleman.
• Ordinarily, you would go to a lawyer or a notary, pay them, and wait
while you get the document. With smart contracts, you simply drop a
bitcoin into the vending machine (i.e. ledger), and your escrow,
driver’s license, or whatever drops into
• smart contracts not only define the rules and penalties around an
agreement in the same way that a traditional contract does, but also
automatically enforce those obligations to your account.

9. BLOCKCHAIN-ETHEREUM
• Ethereum is an open-source, public, blockchain-based distributed
computing platform featuring smart contract (scripting) functionality, which
facilitates online contractual agreements.
• It provides a decentralized Turing-complete virtual machine, the Ethereum
Virtual Machine (EVM), which can execute scripts using an international
network of public nodes.
• Ethereum also provides a cryptocurrency token called "ether" , which can be
transferred between accounts and used to compensate participant nodes for
computations performed.
• The original four members(founders) of the Ethereum team were Vitalik
Buterin, Mihai Alisie, Anthony Di Iorio, and Charles Hoskinson. Dr Gavin
Wood is the Co-Founder of Ethereum.

10. HOW DOES BLOCKCHAIN WORKS ?

11. BLOCKCHAIN- DURABILITY AND
ROBUSTNESS
• Blockchain technology is like the internet in that it has a built-
in robustness.
• It cannot be controlled by any single entity.
• It has no single point of failure.

12. BLOCK CHAIN-A DISTRIBUTED DATABASE
• Information held on a blockchain exists as a shared — and
continually reconciled — database.
• Database isn’t stored in any single location.
• No centralized version of this information exists for a hacker to
corrupt.
• Hosted by millions of computers simultaneously, its data is
accessible to anyone on the internet.

13. BLOCKCHAIN AS GOOGLE DOCS
• With Google Docs (or Google Sheets), both parties have access
to the same document at the same time, and the single version
of that document is always visible to both of them. It is like a
shared ledger, but it is a shared document.
• Blockchain ledgers can be shared with anyone having access to
the nodes.

14. BLOCKCHAIN-APPLICATIONS

15. BLOCKCHAIN-APPLICATIONS(CONTD.)

16. BLOCKCHAIN-APPLICATIONS(CONTD.)

17. THANK YOU