Blockchain security works by having each transaction verified as a digital "block" before entering the system. Computers on the network compete to solve cryptographic puzzles to validate blocks and add them to the blockchain in a verifiable order. This process cuts down on fraud while allowing transactions to occur safely and quickly in a decentralized way. Blockchain has many uses including cryptocurrency, supply chains, financial services, and more.

1. BLOCK CHAIN SECURITY

2. WHO IS SATOSHI NAKAMOTO?

3. WHAT IS BLOCKCHAIN SECURITY?
• Each transaction is a digital ‘block’ that needs to be verified before it’s allowed to enter the
system.
• Questions include:
• Is the money there?
• Are sender and receiver reputable?
• Is the request legitimate? And so forth.
• Each computer on the network competes on unscrambling the answers, and the winning
computer adds this ‘block’ to the ‘blockchain’ in the order that the ‘block’ arrived. The winner
broadcasts his proof to the rest of the network, which checks that proof and verifies it before
queuing the ‘block’ to complete the transaction. Parties involved are assured that
participants have screened and okayed the transaction.
• The process not only cuts down on fraud, such as double spending or spams, but also
transfers funds simply, safely, and fast.

4. HOW DOES BLOCKCHAIN SECURITY
WORK

5. HOW DOES IT OPERATE?
• Economy – centralized, decentralized, distributed
• Question: How do we identify and ignore tampered transactions?

6. USES OF BLOCK CHAIN
• Cryptocurrency
• Supply chain
• Financial Services
• Smart Property
• Healthcare
• Music
• Identity

7. CRYPTOCURRENCIES
https://coinmarketcap.com/all/views/all/

8. BITCOIN
• Bitcoin is open source, managed by UMass Amherst
• https://github.com/bitcoin

9. GETTING STARTED
• Crypto-Currency Exchange – converting
crypto to physical currency or vice versa
• Not regulated by FDIC
• Wild West
• Sketchy
• Question: Why is it sketchy?

10. MINING
• Randomly guessing Nonce
• Currently 12.5 cents to make a block
• Transaction fee awarded to the first to
complete the chain

11. BLOCKCHAIN
DEMO
https://anders.com/blockchain/hash.
html