Block chain and Bitcoin. A blockchain is a data structure that makes it possible to create a digital ledger of transactions and share it among a distributed network of computers.

2. Group Members
1. M Shamim Iqbal
2. Md. Zakaria Hossean
3. Md. Kaiser Ahmed
4. Md. Najmul Hasn Nahid
5. Mehedi Hasan

3. 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.”

4. Blockchain Technology many things
• A blockchain is a data structure that makes it possible to create a digital ledger of
transactions and share it among a distributed network of computers.
• • It uses cryptography to allow each participant on the network to manipulate the
ledger in a secure way without the need for a central authority.
• • Once a block of data is recorded on the blockchain ledger, it’s extremely difficult
to change or remove.
• •When someone wants to add to it, participants in the network — all of which
have copies of the existing blockchain — run algorithms to evaluate and verify the
proposed transaction.

5. Agenda
• Let’s Remember the Blockchain
• What's Ahead for 2020
• The Use Cases

6. Blockchain
=
The Trust Machine

7. Miner
Proof of
Work
Block
Blockchain
(ledger)
NodeNode
Difficulty
Level
Let’s First Remember the Blockchain
BlockchainComponents

8. Blockchain Durability and robustness
• Blockchain technology is like the internet in that it has a built-in robustness.
By storing blocks of information that are identical across its network, the
blockchain cannot:
• Be controlled by any single entity.
• Has no single point of failure.
• Bitcoin was invented in 2008. Since that time, the Bitcoin blockchain has
operated without significant disruption.

9. Where might blockchain use Cryptography

10. network of nodes
• Blockchain and node together they create a powerful second-level network,
a wholly different vision for how the internet can function.
• Every node is an “administrator” of the blockchain, and joins the network
voluntarily (in this sense, the network is decentralized). However, each one
has an incentive for participating in the network: the chance of winning
Bitcoins.

12. Centralized Network

13. Centralize, Decentralized and Distributed Network
• Centralize network: A type of network where all users connect to a central server,
which is the acting agent for all communications.This server would store both the
communications and the user account information.
• Decentralized Network By storing data across its peer-to-peer network,The
decentralized blockchain may use ad-hoc message passing and distributed
networking.Peer-to-peer blockchain networks lack centralized points of
vulnerability that computer crackers .
• Distributed Network ledgers can be public or private and very in their structure
size.
• Users are annonymous

14. What is Cryptocurrency
• A cryptocurrency is a digital or virtual currency designed to work as a
medium of exchange.
• It uses cryptography to secure and verify transactions as well as to control
the creation of new units of a particular cryptocurrency.
• Essentially, cryptocurrencies are limited entries in a database that no one
can change unless specific conditions are fulfilled.

15. There are many Cryptocurrency

16. Some of most valuable cryptocurrency
Name Price
•Bitcoin $6,715
•Ethereum $469
•XRP $0.4715
•EOS $7.93
•LightCoin $83.52
•Dash $245

17. Example of Cryptocurrency

18. Bitcoin
• The one and only, the first and most famous cryptocurrency. Bitcoin serves as a digital gold
standard in the whole cryptocurrency-industry, is used as a global means of payment and is
the de-facto currency of cyber-crime like darknet markets or ransomware.After seven
years in existence, Bitcoin‘s price has increased from zero to more than 650 Dollar, and its
transaction volume reached more than 200.000 daily transactions.
• Then, in early 2009, an anonymous programmer or a group of programmers under an
alias Satoshi Nakamoto introduced Bitcoin. Satoshi described it as a ‘peer-to-peer
electronic cash system.’ It is completely decentralized, meaning there are no servers
involved and no central controlling authority.The concept closely resembles peer-to-peer
networks for file sharing.

19. Satoshi Nakamoto an anonymous
programmer

20. How can I use Bitcoin for Blockchain
• First step

22. Blockchain Applications
• DISTRIBUTED CLOUD STORAGE
Blockchain data storage will become a massive disruptor shortly. (3-5 years)
• Current cloud storage services are centralized — thus you the users must
place trust in a single storage provider. “They” control all of your online
assets.

23. DIGITAL IDENTITY
• Imagine never having to worry about your
digital security every again. It’s a massive
problem in the world.
• Which is now estimated to cost the industry
about $18.5 billion annually, according to a
report releasedThursday by Distil Networks.
• That means for every $3 spent, $1 is going to
ad fraud.

24. Blockchain Identity Use Cases
• Blockchain technology can be applied to identity applications in the
following areas:
• Digital Identities
• Passports
• E-Residency
• Birth Certificates
• Wedding Certificates
• IDs

25. Smart contact:
• These are legally binding programmable
digitized contracts entered on the blockchain.
What developers do is to implement legal
contracts as variables and statements that can
release of funds using the bitcoin network as a
‘3rd party executor’, rather than trusting a single
central authority.

26. DIGITALVOTING
• The greatest barrier to getting electoral
processes online, according to its detractors, is
security. Using the blockchain, a voter could
check that her or his vote was successfully
transmitted while remaining anonymous to
the rest of the world. In 2014, Liberal Alliance,
a political party in Denmark, became the first
organization to use blockchain to vote. With
American voter turnout still shockingly low,
distributed digital voting may represent a way
to enfranchise non-participants.

27. The blockchain enhanced security
Security by the blocks
• A blockchain, as the name implies, is a chain of digital “blocks” that contain
records of transactions. Each block is connected to all the blocks before and
after it. This makes it difficult to tamper with a single record because a
hacker would need to change the block containing that record as well as
those linked to it to avoid detection.

28. Advantages of Blockchain
1. Supply chain management.
• For supply chain management, the blockchain technology offers the benefits of traceability
and cost-effectiveness.
2. Quality assurance.
• If an irregularity is detected somewhere along the supply chain, a blockchain system can
lead you all the way to its point of origin.
3. Smart contracts.
• Time-consuming contractual transactions can bottleneck the growth of a business,
especially for enterprises that process a torrent of communications on a consistent basis.
4.Voting.
• Just like in supply chain management, the promise of blockchains in the aspect of voting all
boils down to trust. Currently, opportunities that pertain to government elections are being
pursued.

29. Disadvantages of Blockchain
• Signature verification. Every blockchain transaction must be digitally
signed using a public-private cryptography scheme such as ECDSA.
• Consensus mechanisms. In a distributed database such as a blockchain,
effort must be expended in ensuring that nodes in the network reach
consensus.
• Redundancy. This isn’t about the performance of an individual node, but
the total amount of computation that a blockchain requires. Whereas
centralized databases process transactions once (or twice).

30. • Payment processing and money transfers
Arguably the most logical use for blockchain is as a means to expedite the transfer
of funds from one party to another.
• Data sharing
Cryptocurrency IOTA launched a beta version of its Data Marketplace in
November, demonstrating that blockchain could be used as a marketplace to share.
• Digital voting
Worried about voter fraud? Well, worry no more with blockchain technology.
Blockchain offers the ability to vote digitally, but it's transparent enough that any
regulators would be able to see if something were changed on the network.
• Blockchain Used For Besides Bitcoin?
Uses of blockchainTechnology