Blockchain Core Concepts Flashcards

Which of the following is the PRIMARY role of a consensus mechanism in a decentralized blockchain network?

Answer: To enable all network participants to agree on the validity and order of transactions, ensuring a single, consistent version of the ledger.

The fundamental purpose of a consensus mechanism is to ensure that all nodes in a distributed network agree on the current state of the ledger. This prevents issues like double-spending and ensures the integrity and consistency of the blockchain without a central authority.

A supply chain consortium wants to implement a blockchain solution to track goods from manufacturer to retailer. They require that only pre-approved and vetted participants can join the network and view transaction details. Which type of blockchain architecture would be most suitable for this scenario?

Answer: Private Blockchain

A private blockchain is the most appropriate choice because it is a permissioned network. Access is restricted to authorized participants, which aligns with the consortium's need for control over who can join and view sensitive supply chain data.

What is the key characteristic of a cryptographic hash function that ensures the immutability of a blockchain?

Answer: The avalanche effect, where a minor change in the input data results in a completely different hash output.

The avalanche effect is crucial for immutability. Each block in a blockchain contains the hash of the previous block. If any data in a previous block is altered, its hash will change completely. This change would cascade through all subsequent blocks, making any tampering immediately evident to the entire network.

In the context of blockchain, what is a smart contract?

Answer: A self-executing program stored on the blockchain that automatically runs when predetermined conditions are met.

A smart contract is essentially a piece of code that lives on the blockchain. It is programmed to execute specific actions automatically based on 'if-then' logic once its predefined conditions have been fulfilled, removing the need for intermediaries.

Which core blockchain concept ensures that all participants have an identical copy of the transaction history, providing transparency and resilience?

Answer: Distributed Ledger

A distributed ledger is a database that is consensually shared and synchronized across multiple sites, institutions, or geographies. In blockchain, this means every node in the network maintains a copy of the ledger, ensuring redundancy and transparency, as all participants see the same version of the truth.

An organization is concerned about the high energy consumption and computational resource requirements of the Proof of Work (PoW) consensus mechanism. Which of the following consensus mechanisms was designed to be a more energy-efficient alternative?

Answer: Proof of Stake (PoS)

Proof of Stake (PoS) was developed as a low-energy alternative to Proof of Work. Instead of requiring miners to solve complex computational puzzles, PoS validators are chosen to create new blocks based on the number of coins they hold and are willing to 'stake' as collateral, which is significantly less resource-intensive.