Blockchain Components

What are the key components of a blockchain?

• transactions, proof of stake, central authority

• mining, private key, public ledger

• blocks, cryptographic hash, consensus mechanism, distributed network

• nodes, encryption, smart contracts

Explain the role of blocks in a blockchain.

• Blocks in a blockchain are designed to prevent any data from being recorded.

• Blocks in a blockchain serve as containers for recording transactions and are linked together in a chain.

• Blocks in a blockchain are used for storing user passwords securely.

• Blocks in a blockchain are only used for decorative purposes.

What is a hash function in the context of blockchain?

• A hash function in blockchain is used to mine cryptocurrencies

• A hash function in blockchain is a type of encryption algorithm

• A hash function in the context of blockchain is a mathematical algorithm that generates a unique fixed-size string of bytes (hash value) from input data, serving as a digital fingerprint to secure blocks of data.

• A hash function in blockchain is a physical device used to store data

How are transactions verified in a blockchain?

• Transactions are verified by a single central authority

• Transactions are verified by random selection of network participants

• Transactions are verified by the weather conditions

• Transactions are verified through a process called consensus among network participants, using mechanisms like Proof of Work (PoW) or Proof of Stake (PoS). Once verified, transactions are added to a block and appended to the blockchain.

What is a public key and private key in blockchain?

• A public key is used for encryption, while a private key is used for decryption

• A public key is used to receive funds and is shared openly, while a private key is used to access and control those funds securely.

• A public key is kept secret, while a private key is shared openly

• A public key is used for personal identification, while a private key is used for encryption

Discuss the role of miners in the blockchain network.

• Miners are responsible for creating new cryptocurrencies.

• Miners have no impact on the security of the blockchain network.

• Miners are primarily involved in marketing blockchain technology.

• Miners validate transactions, create new blocks, and secure the network.

How does blockchain ensure security and immutability of data?

• Blockchain ensures security and immutability of data through magic spells and potions

• Blockchain ensures security and immutability of data by relying on a single centralized authority

• Blockchain ensures security and immutability of data through cryptographic hashing, decentralization, consensus mechanisms, and the append-only nature of blocks.

• Blockchain ensures security and immutability of data by allowing unlimited editing of previous blocks

What is the difference between permissioned and permissionless blockchains?

• Permissioned blockchains are faster than permissionless blockchains.

• Permissioned blockchains have no restrictions on who can participate.

• Permissionless blockchains require a central authority to operate.

• Permissioned blockchains require explicit permission to join and participate, while permissionless blockchains are open for anyone to join and participate.

Discuss the scalability challenges faced by blockchain technology.

• No network congestion

• Unlimited transaction throughput

• Limited transaction throughput, network congestion, growing blockchain size, solutions like sharding and layer 2 protocols

• Decreasing blockchain size

Which type of wallet is known for its convenience but also higher security risk?

• Cold wallet

• • Hardware wallet

• • Hot wallet

• • Paper wallet