TOPIC 2 - BITCOIN/BLOCKCHAIN

Question 1

Whats a software protecol that allows multiple parties to operate

Answer 1

Blockchain

Question 2

What data can be in a blockchain

Answer 2

Anything

Question 3

Some people think of a blockchain as what

Answer 3

append only transaction ledger

Question 4

What properties does blockchain have

Answer 4

Being quickly and easily accessed and shared by many parties

Question 5

What network is a blockchain

Answer 5

a distributed and decentralized network

Question 6

What does blockchain being “distributed mean”

Answer 6

Removes single point of failure

Question 7

What does blockchain being decentralized mean

Answer 7

Removes central authority

Question 8

What does blockchain being immutable mean

Answer 8

Can add to it but hard to alter its history

Question 9

How are updates given

Answer 9

Packaged in blocks and chained together to allow an audit of prior history

Question 10

Ledger is broken up into what

Answer 10

Blocks

Question 11

Every block contains what

Answer 11

A hashed reference to the block before

Question 12

What does blockchain being cryptographically secured mean

Answer 12

last line is repated as the first line in the next block

Question 13

What makes up blockchain

Answer 13

Blocks + chain

Question 14

Every blockchain setup is what

Answer 14

Different

Question 15

What are transaction participants

Answer 15

Sender and receiver

Question 16

What are transaction amounts

Answer 16

How much the bitcoin is plus transaction fee

Question 17

What needs to happen over a purchase

Answer 17

Proof the sender has the amounts being sent

Question 18

What proof from the seller is needed

Answer 18

Proof the sender is authorizing the transaction

Question 19

What is another phrase for public key

Answer 19

Verification key

Question 20

What is a public key

Answer 20

Public addresses - How others transact with you

Question 21

Another phrase for private key

Answer 21

Signing key

Question 22

What is a private key

Answer 22

A password

Question 23

Is it easy to generate a public key and what with

Answer 23

Yes with a private key

Question 24

To authorize a transaction you do what

Answer 24

Sign over using a digital signature

Question 25

Other user can verify you have the private key

Answer 25

can observe your signature and public key

Question 26

What is in a block

Answer 26

A batch of transactions A hash of the previous and current bock A nonce A timestamp

Question 27

What is a nonce

Answer 27

Random number

Question 28

Any user can authorize what

Answer 28

A block

Question 29

Bitcoin blockchain incentive's users to authorize how

Answer 29

Paying the people with free bitcoin

Question 30

Authorizing a new block involves what

Answer 30

Proof of work

Question 31

Blockchains have what protocols

Answer 31

A consensus protocols

Question 32

what is the consensus protocol

Answer 32

Set of rules that determine what kinds of blocks can become part of the chain

Question 33

What are consensus protocols designed to do

Answer 33

resist malicious tampering with a blockchain

Question 34

What is bitcoins proof of work

Answer 34

Bitcoin's consensus protocol

Question 35

Proof of work relies on what

Answer 35

A computational lottery to determine which block to add

Question 36

The participants agree what

Answer 36

That the longest chain of blocks is the "true" blockchain

Question 37

For an attacker to be guaranteed success they need what

Answer 37

More than 50% of the networks computational power

Question 38

Why is attacking bitcoin hard

Answer 38

Buying a majority of the computational power is very expensive so very unlikely

Question 39

Miners group what

Answer 39

Transactions together and make sure they are valid and add a nonce

Question 40

How do miners compete in the lottery

Answer 40

By trying to get a very small value of the hash by cycling through different nonces

Question 41

What do miners get that solve the problem

Answer 41

3.125 bitcoins - reward halves every 4 years Transaction fees

Question 42

When a miner solves the task they do what

Answer 42

Broadcast it to every time they solve the puzzle

Question 43

Difficulty of the hashtag problem is re calibrated how often

Answer 43

every 2 weeks

Question 44

How often should a block be solved

Answer 44

every 10 mins

Question 45

Whats the proof of work with the lottery

Answer 45

As the hash has so many leading zeros is it very difficult so a hack is highly improbable

Question 46

Strength of proof of work

Answer 46

Great security

Question 47

Weakness in proof of work

Answer 47

Electricity cost of mining is enormous and transactions per second are small

Question 48

name of 2 blockchains

Answer 48

Permissionless blockchains Permissioned blockchain

Question 49

Characteristics of a permissionless blockchain

Answer 49

anyone can join the network Low processing time Bitcoins blockchain

Question 50

Characteristics of permissioned blockchains

Answer 50

can put restrictions on who joins Faster processing time as no proof of work

Question 51

Bitcoin was once thought of a method for what

Answer 51

Criminal transactions

Question 52

Has the finance industry came around to bitcoin

Answer 52

Yes

Question 53

What can blockchain technology do

Answer 53

verification of ownership Efficient exchange of ownership

Question 54

What is verification of ownership

Answer 54

Can quickly check the immutable history recorded on a blockchain

Question 55

What is efficient exchange of ownership

Answer 55

Allows for direct transactions without trusted third party Everybody treated the same

Question 56

Why remove the trusted 3rd party

Answer 56

No gatekeeper controls access No ability to change ledger arbitrarily No single point failure

Question 57

Why is no trusted 3rd party good for

Answer 57

Fees

Question 58

big picture implications of blockchain

Answer 58

Removal of many middle people Trust in the network rather than government Near zero transaction costs Financial inclusion for the unbanked