Blockchain technology enables secure digital transactions by allowing information to be distributed without being copied. It operates on a decentralized network where transactions are verified by nodes and recorded in blocks, making it resilient to tampering and enhancing transparency. Despite its advantages, including fraud prevention and cost efficiency, blockchain faces challenges such as security vulnerabilities and data privacy concerns.

1. BLOCKCHAIN
TECHNOLOGY

2. Group
• 1.Name : Azam,Md Syful
. Id : 15-29625-2
• 2.Name : Mahajabin Jorin Khan
. Id : 15-30201-2
• 3. Name : Islam Nayeemul
Id : 15-29624-2

4. What is Block chain Technology?
• By allowing digital information to be distributed but not copied, block chain
technology created the backbone of a new type of internet.
• Block chain is a simple digital platform for Recording and Verifying
Transaction so that other user cant erase them later anyone can see them.
• Originally devised for the digital currency called Bitcoins. Bitcoin has been
called “Digital gold”.

5. History
• No one Knows who invented the Block Chain Technology.
• The idea is come from a paper which is published 10 years ago.
• The Author of the paper is Santoshi Nakamoto.

6. How Block chain Works?
• Someone request to transection

7. How Block chain Works?
• The requested transection is broadcast to a P2P networks consisting of
computers known as node.
• Network of nodes validates the transection and user’s status using known
algorithm.

8. How Block chain Works?
• A verified transection can involve cryptocurrency contacts , records or
information.

9. How Block chain Works?
• Once verified transection is combined with other transection to create a new
block of chain.
• Then new block is added to the existing block chain.

10. How Block chain Works?
• Transection is completed.

12. Inside The Block
• Here Each Block contain some data, The Hash of the block ,and Hash of
the Previous Block

13. Inside The Block
(Data)
• The data that is stored inside a block depends on type of Block chain. For
Example in Bitcoin Block Chain It stores the details of transaction.

14. Inside The Block
(Hash)
• Hash Compared to the Fingerprint. It identify the block and all of it’s
content and it is always unique. Once a block is created it hash has been
calculated. Changing Something inside the block will cost the hash to
changed.

15. Inside The Block
(Hash Of Previous Block)

16. Why Block chain Is More Secure?

17. Why Block chain Is More Secure?

18. Why Block chain Is More Secure?

19. Why Block chain Is More Secure?

20. Why Block chain Is More Secure?

21. Why Block chain Is More Secure?
• Here we temper the Block 2,So the hash will be changed. In term that will
make Block 3 and all following block Invalid. Because they are no longer
hold valid hash of the previous block. So making a change in single block
will make all the following block Invalid.

22. Why Block chain Is More Secure?

23. Block Chain durability Ands Robustness
• Block chain 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 block chain cannot:
• Be controlled by any single entity.
• Has no single point of failure.

24. Block Chain Related Work
• There are so many works done over through blockchain.Related works likes :
Torrent ,Bitcoin.
• Torrent: Torrents utilize the p2p innovation for conveyance of data over the hubs.It is
usually refers a computer files that contains metadata holding various information.a
torrent comes with the extension but it does not contain the actual contents to be
distributed.
• Bitcoin: Bitcoin based on block chain. Bitcoin is a computerized and worldwide cash
formwork money. It transfer directly parson to person without going through bank.
Bitcoins are generated all over the internet by anybody running a free application called
bitcoin miner.

25. A new Level Network
• With block chain technology, the web gains a new layer of functionality.
• Already, users can transact directly with one another — Bitcoin transactions
in 2016 averaged over $200,000 US per day. With the added security brought
by the block chain new internet business are on track to unbundle the
traditional institutions of finance.

26. Transparent And Incorruptible
• The block chain network lives in a state of consensus, one that automatically checks in
with itself every ten minutes. A kind of self-auditing ecosystem of a digital value, the
network reconciles every transaction that happens in ten-minute intervals. Each group
of these transactions is referred to as a “block”. Two important properties result from
this:
• Transparency data is embedded within the network as a whole, by definition it is
public.
• It cannot be corrupted altering any unit of information on the block chain would
mean using a huge amount of computing power to override the entire network.

27. Smart Contract
• Distributed ledgers enable the coding of simple contracts that will execute
when specified conditions are met. Ethereum is an open source block chain
project that was built specifically to realize this possibility. Still, in its early
stages , Ethereum has the potential to leverage the usefulness of block chains
on a truly world-changing scale.

28. The sharing economy
• With companies like Uber and AirBnB flourishing, the sharing economy is
already a proven success. Currently, however, users who want to hail a ride-
sharing service have to rely on an intermediary like Uber. By enabling peer-
to-peer payments, the block chain opens the door to direct interaction
between parties — a truly decentralized sharing economy results.

29. Problems in conventional System
• User data is getter enormous day by day
• Maintaining connectivity continuously to server
• Slow data transfer rate for large connected users
• If server gets disconnected
• If server gets hacked

30. Future Of Block Chain
DISTRIBUTED CLOUD STORAGE: Block chain 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.
On the other hand with the Blockchain, this can become decentralized. For instance,
Storj is beta-testing cloud storage using a Blockchain-powered network to improve
security and decrease dependency. Additionally, users (you) can rent out their excess
storage capacity, Airbnb-style, creating new marketplaces

31. Limitation of Block Chain Technology
• Security, security and security. Given the technology is primarily being
considered within the Financial Services space, Banks and similar
organizations need to be 250% sure that their customer funds will be safe.
• Over $2bn of Bitcoins have been stolen, hacked or scammed since 2009
(around 20% of all bitcoins). This includes the $61m hack of the Bitfinex
Exchange in Hong Kong and the DAO attack (c $53m)

32. Advantages Of Block Chain
• Fraud prevention
• Protection from government unnecessary interference
• Decentralized data storage
• Reliability
• Cost efficiency

33. Disadvantages Of Block Chain
● Crime
● Storage problem
● Privacy
● Unavoidable security flaws
● Control flaws

34. Conclusion
Block chain has brought a revolutionary change in decentralized management
system. Because of its invention transaction has become easier and it provides
security than before. Time is beings saved due to this and people don’t need to
go physically to transfer money. But block chain also has some problems as it
can leak all the personal information of a customer.