Blockchain Flashcards
(158 cards)
1
Q
Supernodes in which architecture
A
Decentralized
2
Q
Control is distributed vs Task and Data is distributed
A
Decentralized Vs Distributed
3
Q
Blind Signature in which predecessor of blockchain
A
Digicash
4
Q
Spam email on PoW system and DDoS in which predecessor of blockchain
A
HashCash
5
Q
Byzantine Fault Tolerance consensus based non fungible which predecessor of blockchain
A
Bitgold
6
Q
Compelling components of Bitcoin
-Value(BTC), Distribution(network of nodes) and Transaction
-Distribution(network of nodes) , Consensus(PoW) and Tokens(BTC)
-Value(BTC), Distribution(network of nodes) and Consensus(PoW)
-Distribution(network of nodes) , Value(BTC) and Agreement(PoW)
A
Value(BTC), Distribution(network of nodes) and Consensus(PoW)
7
Q
Accounting type of Bitcoin
A
Unspent Transaction Output(UTXO)
8
Q
12 subsections in Bitcoin white paper
A
Introduction
Transactions
Timestamp Server
POW
Network
Incentive
Reclaiming Disk Space
Simplified Payment Verification
Combining and Splitting value
Privacy
Calculations
Conclusion
9
Q
Elements in a block
A
Block version
Hash of previous block
Merkel tree root hash
nBits(Difficulty level) - Hash of the header is below the target hash
Nounce - Variable decided by miner to keep block hash below target hash
Timestamp - Unix timestamp
10
Q
P2P networtk use cases
A
Cryptocurrencies
Search engines
Online streaming
Marketplaces
IPFS
11
Q
Server based newtork examples
A
Microsoft windows 2012 and Windows 2016
12
Q
Blockchain distributed P2P architecture limitation
A
Scalability due to data replication of blocks in each node
Hard fork events in blockchain where open source code can be altered in a node
Lack of regulation to allow illegal activities
13
Q
Decentralized, transparent, enable tokenization and open to all and Immutable, which blockchains?
A
Public Blockhain (Bitcoin), Ethereum and Litecoin
14
Q
Distant hashing algorithm and faster transaction confirmations, which blockchain?
A
Litecoin
15
Q
Smart contracts, which blockchain?
A
Ethereum
16
Q
Consensus mechanism in public blockchain
A
POW, POS and DPOS
17
Q
Tranditional Financial Service on public blockchain, example?
A
DeFi
18
Q
Permissioned Blockchain another name?
A
Private Blockchain
19
Q
Examples of private blockhain
A
Hyperledger Fabric, Corda, Quorum
20
Q
Consensus mechanism in private blockchain
A
Practical Byzantine Fault Tolerance, Proof of Authrotity, Round Robin
21
Q
Consensus in private blockchain where majority wins
A
Practical Byzantine Fault Tolerance
22
Q
Consensus in private blockchain where preselected validators agree in sequence
A
Proof of Authrotity
23
Q
Consensus in private blockchain where preselected validators agree by taking turns
A
Round Robin
24
Q
Hybrid blockchain example
A
Dragonchain, XinFin
25
Cross Org Collab which type of blockchain
Hybrid
26
Examples of consortium blockchain
R3 Corda for Financial sector, B3i for Insurance industry
27
Use cases of consortium blockchain
Cross border payment, Healthcare and Supply chain
28
Max metadata size with bitcoin transaction
1 MB
29
Total cap of Bitcoin
21 million
30
The Merge
Movement from PoW to PoS in Ethereum blockchain resulted in increased secuity and decreased energy consumption
31
Shepella
Upgrade in Etehreum blockchain where stakers can withdraw their stake holdings
32
GAS tokens
Used in NEO blockhain(Ethereum of China) as its cryptocurrency
33
Is Mining happens in NEO blockchain
No, Its 100% mined
34
Hyperledger by whom?
Linux foundation
35
What supports creating blockchains without cryptocurrencies
Hyperledger, Corda and Quorum
36
EOS blockhain block producers selection process
Same as distributed Proof of Stake system granting access to funds to stakeholders by the person initiating the transaction
37
EOS blockhain charges a fee for a transaction, True or False
False
38
What is the consensus mechanism in EOS blockchain
DPoS
39
Corda blockchain language
JVM based using Kotlin
40
Corda does not adhere to single consensus algo, true or false
True
41
Which private blockhain does not permit to create native cryptocurrencies and uses smart contracts?
Corda blockchain
42
Which blockchain technology follows transaction level privacy + network level transparency?
Quorum
(Privacy is ensured by segregating the public ledger into public and private ledgers)
(Hash of private transaction is visible on public ledger and decryption keys are with authorized parties only)
43
Quorum uses Ethereum blockchain method, True or False?
True
44
Consensus in Quorum
RAFT and Istanbul BFT
45
Consensus in Corda
No fixed method. Based on notary nodes
46
Consensus in Ethereum
Proof of Stake
47
Consensus in Hyperledger
PBFT
48
Consensus in Bitcoin
POW
49
What is another name for exchangeable tokens
Fungible
50
Functions of tokens
Entry point for blockchain applications
Individual qualifications for voting
To enhance user experience
Store of value as digital asset
Exchange of value
Contains smart contracts defing property and functions for the token
51
ERC-20 vs ERC-721
Ethereum fungible token std vs NFT token std
52
ERC-1155
Covers both fungible and non fungible tokens, use case is Gaming applications
53
ERC-777
Advanced fungible token standard. Introduces hooks that can triggered when tokens are sent or received
Solution for "token locking" where ERC-20 tokens gets stuck
54
ERC-223
Solution for "token loss" where ERC-20 tokens where lost to contracts not equipped to handle them. Allows compatible contracts to engage in a transaction
55
ERC-865
Alows users to pay transaction fees using tokens other than eth
56
ERC-875
Supports transfer of multiple non fungible tokens in one transaction
Transaction fee can be paid in the token being used to transafer instead of eth
57
Merkel Tree
Sumarizes transaction in a block
Leaf node hash(hash of its transaction) and non-leaf node hash(has of its children)
58
SPV validation in which wallets
Mobile wallets
59
What is Simple Payment verification(SPV) for mobile wallets
Doesn't require to download entire blockchain to confirm transaction
60
Highest level of security in which wallets
Hardware wallets
61
What is P2PKH format
Pay to Public key hash
62
Elliptic curve cryptography
Bitcoin uses this to get public key using private key. It is secured than RSA the asymmetric or public key encryption
63
Public key address hashing method in bitcoin
Its hased using SHA256 and then rehashed using ripe MD160 and the hashed string is encoded to base58
64
What is encrypting and decrypting using a single key
Symmetric key or secret key cryptography, AES is the example
65
Example of symmetric key cryptography
AES
66
What is cryptograhic hash function example
SHA
67
what is the nonce value length
2^68
68
Block version contains what
Blockchain protocol
69
Most secure public key encryption example
ECC
70
Digital fingureprint another name
Hash
71
Block chain project for cross border transaction
Steller
72
Block chain project called "Chinese Ethereum"
Neo
73
Blockchain project having smart contracts
Ethereum
74
Blockchain access layer
It has block, network and transactions
75
Secure communication and digital signature creation which cryptography
RSA (Public or asymmetric key cryptography example)
76
What is meme pool
Pool of unconfirmed transactions that ware waiting to be included on a blockchain
77
What helps to create tokens and smart contracts in Hyperledger
Chaincode
78
Mining helps network security, true or false?
True
79
What are different types of mining?
CPU, GPU, ASIC
80
In the UTXO model, what does a node represent in the directed acyclic graph (DAG)?
Output of a transaction
81
Which blockchain uses account-based model?
Ethereum
82
In the account-based model, what is used to mitigate replay attacks?
Using Nonce
83
How is the global state represented in the UTXO model?
Using directed acyclic graph (DAG) of transaction outputs
84
In the account-based paradigm, how is signature verification done?
Using r, s, and v parameters
85
It tolerates upto 1/3 of traitor generals
PBFT
86
Which consensus uses economic incentives to deter malicious behavior and promote consensus
PoW
87
Which consensus introduces state machine replication to ensure consistency of system's state
PBFT-SMaRt
88
Which consensus is more popular in Supplychain and Healthcare
BFT and PBFT
89
Multiple fake identities is which type of attack
Sybil attack
90
Voting for selecting validators which consensus mechanism
Delegated Proof of Stake
91
Identified and trusted validators rather than financial stakes (more for private or consortium blockchains)
Proof of Authority
92
Utilizing space on devices for validate and mine blocks and enegy efficient alternative to PoW
Proof of Space
93
Nodes are identified as clients, replicas and leaders in which consensus mechanism
PBFT
94
Deterministic execution in which consensus mechanism
PBFT
95
This consensus mechanism does not rely on mining or staking
PBFT
96
Three roles in PBFT
Clients, replicas and leaders
97
Consensus mechanism in which immediate finality is achieved without waiting for additional confirmation of blocks
PBFT
98
Higher communication overhead in which consensus mechanism
PBFT
99
High enery consumption in which consensus mechanism
PoW
100
Highest scalability in which consensus mechanism
Delegate PoS
101
Highest security in which consensus mechanism
PoW
102
Highest decentralization in which consensus mechanism
PoW
103
Highest finality in which consensus mechanism
PoS, DPoS and PBFT
104
Private or consortium blockchain uses mostly which consensus mechanisms
PoA and PBFT
105
Gaming uses mostly which consensus mechanism
DPoS
106
DeFi uses mostly which consensus mechanism
PoS and DPoS
107
Digital governance system uses mostly which consensus mechanism
DPoS and PBFT
108
Asynchronous byzantine fault tolerance
Honeybadger byzantine fault tolerance
109
Faster block finality which consensus mechanism
Tendermint
110
Time ordered record of events in which consensus mechanism
Proof of History
111
Miners invest in virtual mining machines in which consensus mechanism and alternative to PoW
PoB
112
PoS and PoB difference
Coins are not destroyed in PoS whereas they are destroyed in PoB
113
Which is faster PoW or PoB
PoW
114
Which cryptocurrency uses PoB
Slimcoin
115
Alogrand consensus model is used in which consensus mechanism
Proof of Weight
116
One advantage and disadvantage of Proof of Weight
Scalability and Lack of incentive
117
Lite nodes vs Full nodes in which consensus mechanism
Leased PoS
118
Which consensus mechanism used by waves platform
LPoS
119
Permission based access is provided by which popular blockchains
Hyperledger and Multichain platforms
120
Setting difficulty level in Pow is what aspect of blockchain design
Parameters
121
Atomic exchanges enables what in blockchain design
Interoperability between different blockchains or departments within the same blockchain
122
Multiple signatures enables what in blockchain design
Multi party approval system where majority agreement is required before spending cryptocurrencies
123
Etherisc and Tracer
Blockhain in reinsurance / DeBeers blockchain supply chain application
124
Which firm introduced auditing of cryptocurrencies
PWC
125
Mobile election voting platform using blockchain
Votem and Voatz
126
Donations and Charity application using blockchain
-Unicef Australia and Cudo donate
-BitGive
-Bitdonate
-UnicefNZ
BitGive
127
Blockchain platform where people can mine for charity
-Unicef Australia and Cudo donate
-BitGive
-Bitdonate
-UnicefNZ
Unicef Australia and Cudo donate
128
Blockhain based agricultural supply chain product
-AgriDigital
-CropChain
-IntelloLabs
-Agri10x
AgriDigital
129
Blockchain platform that connects farmers and buyers
-AgriDigital
-CropChain
-IntelloLabs
-Agri10x
Agri10x
130
Blockchain plalform to provide end-to-end visibility of the supply chain and ensures farmers are paid fairly
-AgriDigital
-CropChain
-IntelloLabs
-SourceTrace
CropChain
131
Blockchain platform to improve the quality of the crops. Uses ML to analyze images of the crops
-AgriDigital
-SourceTrace
-IntelloLabs
-Agri10x
IntelloLabs
132
Blockchain platform for farmer to manage their inventory and connect with buyers
-AgriDigital
-CropChain
-SourceTrace
-Agri10x
SourceTrace
133
Chain of Things used where
-IoT build on Maru
-IOTA
-Riddle&Code
-Trust Square
IoT build on Maru
134
Employs directed acylic graph called Tangle
-IoT build on Maru
-IOTA
-Riddle&Code
-Trust Square
IOTA
135
Enhances the security of IoT devices by providing verification of digital identity of machines
-IoT build on Maru
-IOTA
-Riddle&Code
-Trust Square
Riddle&Code
136
Brings IoT devices on Blockchain for supple chain management
-IoT build on Maru
-IOTA
-Riddle&Code
-Trust Square
Trust Square
137
Chain of Custody as one of the areas to use blockchain in which industry
Blockhain in legal industry
138
What cryptography used by HashCash
SHA-1
139
Free financial system over the internet in which predecessor of blockchain
B-Money
140
Digital gold currency company in which predecessor of blockchain
E-gold
141
Which network allows precison search using hash functions for faster database lookups
Structured P2P network
142
Which type of blockchains have transparent in transactions and decentralized network?
Public blockchains
143
Network access is restricted and transactions are confidential in which type of blockchain?
Private
144
Hyperledger developed by?
Linux foundation
145
Administration comparison
Bitcoin - Decentralized P2P network
Ethereum - None
Hyperledger - Linux foundation
Corda - R3 consortium
Quorum - JP Morgon
146
Consensus comparison
Bitcoin - PoW
Ethereum - PoS
Hyperledger - PBFT
Corda - Based on notory nodes(Transaction validity and transaction uniqness)
Quorum - RAFT and Istanbul FT
147
Smart Contract comparison
Bitcoin -none
Ethereum - no legal binding
Hyperledger - no legal binding
Corda - Legally bound
Quorum - Legally bound
148
Blockhain in Agriculture
Bext360, Agridigital and Grassroots Cooperatives
149
Types of Tokens used in DeFI
-Trade,Utility,Vote
-Utility,Governance,Trade
-Crypto,Utility,Governance
-Crypto,Trade,Utility
Crypto(have monitory value), Utility(use product or services) and Governance(allow vote for change)
150
Yield farming
Investments in DeFI to maintain liquidity
151
DeFI platforms examples
MakerDAI(get DAI for ethereum, USDC or BAT),
Uniswap(decenralized exchange to trade ethereum),
Compound(earn interest and lending and borrowing cryptocurrenies),
Yearn.finance(less technical and yield farming)
152
What are sythentic assests
Derivatives
153
Crypto wallet insurance example
-Etherisc
-Nexus Mutual
-Riddle&Code
-Trust Square
Etherisc
154
Smart contract cover provided by which product
-Etherisc
-Nexus Mutual
-Riddle&Code
-Trust Square
Nexus Mutual
155
What is TVL in DeFI insurance
Total Value Locked (Fiat value of crypto tokens)
156
Which cryptocurrency is commonly referred to as stablecoin and used in DeFI
-USDC
-USDT
-Dogcoin
Slimcoin
USDT
157
What does ERC stand for
-Ethereum request for comments
-Ethereum requests for commonwealth
-Ethereum requirements corporation
-Euro requests for comments
Ethereum request for comments
158
Predecessors of Bitcoin
Digicash by David Chaum uses blind signatures
HashCash by Adam back uses DOS attack prevention for email spam
B-Money by Wei Dai as free financial system
E-gold by Douglas Jackson and Barry Downey as digital gold currency
Bit-gold by Nick Sabo as decentralized virtual currency uses BFT consensus
