IT2864 Week 3

What is a consensus algorithm in blockchain?

• A consensus algorithm in blockchain is a mechanism used to encrypt transactions and secure the blockchain.

• A consensus algorithm in blockchain is a mechanism used to randomly select participants to validate transactions and add them to the blockchain.

• A consensus algorithm in blockchain is a mechanism used to centralize control and decision-making in the network.

• A consensus algorithm in blockchain is a mechanism used to achieve agreement among participants in a distributed network on the validity of transactions and the order in which they are added to the blockchain.

Which consensus algorithm is used by Bitcoin?

• Delegated Proof of Stake (DPoS)

• Proof of Work (PoW)

• Proof of Stake (PoS)

• Proof of Authority (PoA)

What is a cryptocurrency?

• A cryptocurrency is a physical form of currency that uses cryptography for security.

• A cryptocurrency is a digital or virtual form of currency that uses cryptography for security.

• A cryptocurrency is a type of stock market investment.

• A cryptocurrency is a government-issued form of currency.

What is the purpose of decentralization in blockchain?

• Decentralization in blockchain is used to centralize control and decision-making power in a single entity.

• The purpose of decentralization in blockchain is to increase transaction fees and make the system more expensive.

• Decentralization in blockchain is aimed at reducing transparency and security of data by limiting access to a few participants.

• The purpose of decentralization in blockchain is to ensure transparency, security, and immutability of data by distributing control and decision-making power across a network of participants.

What are the advantages of decentralization in blockchain?

• Increased security, improved transparency, enhanced privacy, and reduced costs.

• Unreliable security, unclear transparency, compromised privacy, and increased costs.

• No security, no transparency, no privacy, and high costs.

• Decreased security, limited transparency, compromised privacy, and increased costs.

What is a private blockchain?

• A private blockchain is a type of blockchain that is open to anyone who wants to participate.

• A private blockchain is a type of blockchain that is restricted to a specific group of participants.

• A private blockchain is a type of blockchain that is controlled by a central authority.

• A private blockchain is a type of blockchain that is used for public transactions.

What is a public blockchain?

• A public blockchain is a database that is controlled by a single entity and is not open to public participation.

• A public blockchain is a centralized and opaque ledger that is only accessible to a select group of individuals.

• A public blockchain is a technology that is used exclusively by government organizations and is not available to the general public.

• A public blockchain is a decentralized and transparent ledger that is open to anyone to participate and view.

What is a permissioned blockchain?

• A permissioned blockchain is a type of blockchain that is controlled by a single entity.

• A permissioned blockchain is a type of blockchain where access and participation are restricted to a specific group of participants who have been granted permission.

• A permissioned blockchain is a type of blockchain that does not require any authentication or authorization.

• A permissioned blockchain is a type of blockchain that is open to anyone and everyone.

What are the security challenges in blockchain?

• 51% attack, double spending, smart contract vulnerabilities, and privacy concerns

• Blockchain scalability, network congestion, and regulatory compliance

What is the role of miners in blockchain?

• Miners control the blockchain network.

• Miners are responsible for securing user data on the blockchain.

• Miners create new cryptocurrencies.

• Miners validate and add transactions to the blockchain.