Certainly! Here’s a comprehensive 90-question Blockchain and Cryptography MCQ Test Quiz with answers, organized into three sections:
Table of Contents
Section 1: Blockchain Fundamentals MCQ
- What is a blockchain?
a) A centralized database
b) A networking protocol
c) A decentralized ledger ✅
d) A type of database - What is the first block of a blockchain called?
a) Seed Block
b) Origin Block
c) Genesis Block ✅
d) Root Block - Who introduced blockchain technology?
a) Gavin Wood
b) Satoshi Nakamoto ✅
c) Charles Hoskinson
d) Vitalik Buterin - Which of the following is a key feature of blockchain?
a) Immutability ✅
b) Insecure data transfer
c) High centralization
d) Dependence on a single server - Which is the first cryptocurrency to use blockchain technology?
a) Ripple
b) Litecoin
c) Ethereum
d) Bitcoin ✅ - What is the primary purpose of blockchain technology?
a) To replace all traditional databases
b) To provide a secure and transparent record of transactions ✅
c) To create cryptocurrencies
d) To centralize data storage - What type of database is blockchain?
a) Centralized relational database
b) Decentralized ledger ✅
c) Distributed cache
d) Hierarchical - What is the unit structure of a blockchain called?
a) Node
b) Transaction
c) Block ✅
d) Record - What is the main advantage of decentralization in blockchain?
a) Reduced security risks ✅
b) Faster central decision-making
c) Increased dependency on intermediaries
d) Higher data redundancy - What does the term “distributed ledger” imply in blockchain?
a) Data is stored offline
b) Data is copied and synchronized across multiple locations ✅
c) Data is stored in a central server
d) Data can be edited by any participant - What does a blockchain ledger store?
a) Cryptocurrency wallets
b) Node-specific information
c) Any type of verified data ✅
d) Only monetary transactions - What is the main component of a blockchain that contains transaction data?
a) Chain
b) Node
c) Block ✅
d) Hash - What is the purpose of a Merkle tree in blockchain architecture?
a) Generating private keys
b) Storing cryptocurrency
c) Encrypting data
d) Efficiently verifying data integrity ✅ - What are the pillars of blockchain technology?
a) Transparency
b) Immutability
c) Decentralization
d) All of the Above ✅ - In blockchain, which tree stores all the transactions in a block by producing a digital fingerprint of the entire set of transactions?
a) Merkle ✅
b) Binary
c) AVL
d) Red-black - Which of the following is not a blockchain component?
a) Ledger
b) Wallet
c) Certificate authority ✅
d) Hash - What is a smart contract?
a) A contract with artificial intelligence
b) The ability to send money via blockchain
c) A contract on a blockchain between two parties with specific requirements ✅
d) A digital signature - What is a fork in blockchain?
a) A new cryptocurrency
b) A split in the blockchain network due to protocol changes ✅
c) A type of wallet
d) A mining tool - What is mining in blockchain?
a) Deleting old transactions
b) Creating new blocks by solving complex mathematical problems ✅
c) Sending cryptocurrency
d) Encrypting data - What consensus mechanism does Bitcoin use?
a) Proof of Stake
b) Proof of Work ✅
c) Delegated Proof of Stake
d) Practical Byzantine Fault Tolerance - What is the maximum number of Bitcoins that can ever exist?
a) 10 million
b) 21 million ✅
c) 100 million
d) Unlimited - Which of the following is a public blockchain?
a) Hyperledger Fabric
b) Ethereum ✅
c) Corda
d) Quorum - What is a node in blockchain?
a) A central server
b) A participant in the network that maintains a copy of the blockchain ✅
c) A type of cryptocurrency
d) A smart contract - What is the role of cryptographic hash functions in blockchain?
a) Encrypt data
b) Compress data
c) Link blocks and ensure data integrity ✅
d) Generate public keys - Which of the following is a characteristic of blockchain?
a) Centralized control
b) Immutability ✅
c) Single point of failure
d) Limited transparency - What is the function of a digital signature in blockchain?
a) Encrypt data
b) Authenticate transactions and ensure non-repudiation ✅
c) Compress data
d) Generate public keys - What is a private blockchain?
a) A blockchain accessible to anyone
b) A blockchain with restricted access, controlled by an organization ✅
c) A blockchain used for cryptocurrencies
d) A blockchain without consensus mechanism - What is a public key in blockchain?
a) A secret key
b) A key used to decrypt data
c) A key shared publicly to receive transactions ✅
d) A key used to mine blocks - What is the purpose of consensus algorithms in blockchain?
a) Encrypt data
b) Ensure all nodes agree on the state of the blockchain ✅
c) Compress data
d) Generate public keys - What is the main benefit of using blockchain in supply chain management?
a) Increased costs
b) Reduced transparency
c) Enhanced traceability and transparency ✅
d) Centralized control
Section 2: Cryptography in Blockchain MCQ
- What is cryptography?
a) Study of numbers
b) Study of data compression
c) Study of secure communication techniques ✅
d) Study of algorithms - Which cryptographic algorithm is commonly used in blockchain?
a) DES
b) RSA
c) SHA-256 ✅
d) Blowfish - What does SHA stand for in SHA-256?
a) Secure Hash Algorithm ✅
b) Secure Hypertext Algorithm
c) Simple Hash Algorithm
d) Secure Hacking Algorithm - What is the output size of SHA-256?
a) 128 bits
b) 160 bits
c) 256 bits ✅
d) 512 bits - What is a hash function?
a) A function that encrypts data
b) A function that compresses data
c) A function that maps data of arbitrary size to fixed-size values ✅
d) A function that decrypts data - What property of hash functions ensures that it’s computationally infeasible to find two different inputs that produce the same output?
a) Pre-image resistance
b) Collision resistance ✅
c) Avalanche effect
d) Determinism - What is the avalanche effect in cryptography?
a) A small change in input causes a significant change in output ✅
b) A large change in input causes a small change in output
c) No change in output despite changes in input
d) Output remains constant - What is public-key cryptography?
a) Cryptography using a single key
b) Cryptography using symmetric keys
c) Cryptography using a pair of keys: public and private ✅
d) Cryptography without keys - In public-key cryptography, what is the private key used for?
a) Encrypting data
b) Decrypting data ✅
c) Generating hash
d) Compressing data - Which of the following is a symmetric encryption algorithm?
a) RSA
b) AES ✅
c) ECC
d) Diffie-Hellman - What is the main difference between symmetric and asymmetric encryption?
a) Symmetric uses two keys; asymmetric uses one
b) Symmetric uses one key; asymmetric uses two ✅
c) Both use the same number of keys
d) Symmetric is slower than asymmetric - What is a digital signature?
a) A handwritten signature
b) A type of encryption
c) A cryptographic technique to validate the authenticity and integrity of a message ✅
d) A password - Which algorithm is commonly used for digital signatures?
a) SHA-256
b) RSA ✅
c) AES
d) DES - What is the role of a nonce in blockchain mining?
a) To encrypt data
b) To decrypt data
c) To find a value that satisfies the proof-of-work condition ✅
d) To compress data - What is the purpose of proof-of-work in blockchain?
a) To speed up transactions
b) To ensure consensus by requiring computational effort ✅
c) To encrypt data
d) To store data - Which of the following ensures data integrity in blockchain?
a) Encryption
b) Hash functions ✅
c) Compression
d) Decryption - What is key management in cryptography?
a) Managing passwords
b) Managing encryption and decryption keys securely ✅
c) Managing user accounts
d) Managing databases - What is the main purpose of cryptographic hashing in blockchain?
a) To encrypt transaction data. b) To compress large files c) To ensure data integrity and link blocks securely ✅ d) To create public keys from private keys
- What is key pair generation in public-key cryptography?
a) Generating a random number
b) Generating public and private keys that are mathematically linked ✅
c) Generating two passwords
d) Generating encryption certificates - Which one of the following ensures message authentication and non-repudiation?
a) Hash functions
b) Symmetric encryption
c) Digital signatures ✅
d) Plain text - In cryptography, which method transforms readable data into an unreadable format?
a) Hashing
b) Encrypting ✅
c) Decoding
d) Compression - Which of the following is not a property of a good hash function?
a) Determinism
b) Fast computation
c) Collision prone ✅
d) Avalanche effect - What is cryptanalysis?
a) Encrypting plaintext
b) Decrypting ciphertext without knowing the key ✅
c) Creating digital wallets
d) Key generation - Which cryptographic technique is most secure against quantum attacks?
a) RSA
b) ECC
c) Post-quantum cryptography ✅
d) AES - Which algorithm is used by Bitcoin to hash block headers?
a) AES
b) SHA-256 ✅
c) SHA-1
d) MD5 - Which is more efficient for mobile devices: RSA or ECC?
a) RSA
b) ECC ✅
c) Both equally
d) Neither - In asymmetric encryption, which key is shared publicly?
a) Private key
b) Public key ✅
c) Session key
d) Secret key - Which of the following algorithms is used to generate digital signatures in blockchain?
a) SHA-256
b) ECDSA ✅
c) AES
d) DES - What is the main objective of cryptography in blockchain?
a) Enable multiple consensus models
b) Allow mining
c) Ensure secure communication and data integrity ✅
d) Minimize storage - What is elliptic curve cryptography (ECC)?
a) Symmetric key algorithm
b) Public key cryptography using elliptic curves ✅
c) Hashing algorithm
d) Signature compression technique
Section 3: Advanced Blockchain Concepts MCQ
- What is a 51% attack in blockchain?
a) Taking over half of the market
b) An attack where a group controls over 50% of the network’s mining power ✅
c) Changing half the blocks
d) Losing 51% of coins - Which blockchain feature helps prevent double-spending?
a) Smart contracts
b) Proof of stake
c) Consensus mechanism ✅
d) Wallet address - What is a DAO in the blockchain context?
a) Distributed Audit Order
b) Decentralized Autonomous Organization ✅
c) Digital Accounting Operator
d) Decentralized Application Order - Which blockchain is primarily known for smart contract functionality?
a) Bitcoin
b) Ripple
c) Ethereum ✅
d) Litecoin - What is gas in Ethereum?
a) Cryptocurrency unit
b) A fuel charge to run transactions and smart contracts ✅
c) Type of transaction
d) Block header - What is a DApp?
a) Data App
b) Desktop Application
c) Decentralized Application ✅
d) Digital Address Protocol - What consensus mechanism does Ethereum 2.0 use?
a) Proof of Work
b) Proof of Stake ✅
c) Byzantine Fault Tolerance
d) Delegated Proof of Work - Which layer of blockchain manages the actual consensus mechanism?
a) Application layer
b) Network layer
c) Consensus layer ✅
d) Transport layer - Which one is a Layer 2 scaling solution for Ethereum?
a) Bitcoin Cash
b) Polygon (MATIC) ✅
c) Litecoin
d) Avalanche - What is a hash pointer in blockchain?
a) A pointer to the block height
b) A link to the block’s index
c) A pointer to previous block and its hash ✅
d) A data encryption pointer - What is slashing in blockchain staking?
a) Rewarding honest validators
b) Cutting down transaction fees
c) Penalizing malicious or lazy validators ✅
d) Creating forked chains - Which language is commonly used to write Ethereum smart contracts?
a) Rust
b) Solidity ✅
c) Java
d) Python - What does interoperability in blockchain refer to?
a) Speeding up transactions
b) Supporting multiple tokens
c) Ability of different blockchains to communicate ✅
d) Reducing storage - Which blockchain platform is focused on enterprise solutions?
a) Ethereum
b) Hyperledger Fabric ✅
c) Solana
d) Tezos - What is the main purpose of a whitepaper in blockchain projects?
a) Brand building
b) Explaining the project’s vision, technology, and tokenomics ✅
c) Listing exchanges
d) Writing code - Which of these is NOT a real consensus algorithm?
a) PoS
b) PBFT
c) PoC
d) PoR (Proof of Romance) ✅ - Which consensus algorithm is energy-efficient?
a) Proof of Work
b) Proof of Stake ✅
c) Proof of Capacity
d) Proof of Burn - What are oracles in blockchain?
a) Mining nodes
b) Smart contract validators
c) Services that connect blockchain with external data ✅
d) Decentralized ledgers - What is tokenization?
a) Encrypting user data
b) Creating NFTs
c) Representing real-world assets on the blockchain ✅
d) Hashing coins - What is a wrapped token?
a) A token used for staking
b) A token stored in cold wallet
c) A token pegged to another asset on a different blockchain ✅
d) Token used for smart contracts - What is a sidechain?
a) Another form of blockchain attack
b) A secondary blockchain connected to a main chain ✅
c) A hard fork
d) A digital signature type - What is cold storage in cryptocurrency?
a) Storing coins on cloud
b) Storing cryptocurrency in offline wallets ✅
c) Freezing tokens
d) Burning coins - What does NFT stand for?
a) New Financial Token
b) Non-Fungible Token ✅
c) National Funding Token
d) Non-Fundable Trust - Which of these is a blockchain explorer?
a) Metamask
b) EtherScan ✅
c) CoinMarketCap
d) TrustWallet - Which programming language is used for Solana smart contracts?
a) Solidity
b) C++
c) Rust ✅
d) Go - What is finality in blockchain?
a) Starting a transaction
b) Time before mining
c) Assurance that a transaction cannot be reversed ✅
d) Completing a block - Which of these is an example of a governance token?
a) ETH
b) USDT
c) UNI ✅
d) BTC - What is front-running in blockchain?
a) Confirming transactions
b) Mining fast blocks
c) Executing a transaction based on knowledge of future trades ✅
d) Verifying NFT ownership - Which of these coins use privacy-enhancing technology?
a) Monero ✅
b) Ethereum
c) Bitcoin
d) Solana - What is Zero-Knowledge Proof in blockchain?
a) Encryption method
b) A way to prove information without revealing the data ✅
c) Digital wallet technique
d) Random key generation
