CBP - Certified Bitcoin Professional Bitcoin Mining and Consensus Questions and Answers

Question 1

Which of the following best describes the primary purpose of the difficulty adjustment in the Bitcoin protocol?

Accepted Answer

To maintain a consistent block generation time of approximately 10 minutes.

Answer

The difficulty adjustment is a core mechanism in Bitcoin's consensus protocol that recalibrates the complexity of the cryptographic puzzle miners must solve. This adjustment occurs every 2,016 blocks to ensure that, on average, a new block is added to the blockchain approximately every 10 minutes, regardless of changes in the total network hashing power.

Question 2

A mining pool operator is analyzing the latest block found by their pool. What is the very first transaction they should expect to see within the block's data structure?

Accepted Answer

The coinbase transaction.

Answer

The first transaction in any valid Bitcoin block must be the coinbase transaction. This special transaction is created by the miner and serves two purposes: it allows the miner to claim the block reward (the block subsidy plus all transaction fees from the block) and it has no inputs, effectively creating new bitcoin.

Question 3

What is the core principle of Nakamoto Consensus that allows nodes to agree on the valid version of the blockchain in the event of a temporary fork?

Accepted Answer

The chain with the most accumulated Proof of Work (the longest chain) is considered valid.

Answer

Nakamoto Consensus combines Proof of Work with the 'longest chain' rule. In the case of competing chains (a fork), the network considers the chain with the most cumulative computational work expended on it to be the authoritative one. Because more work results in a longer chain of blocks, this is often referred to as the 'longest chain rule'.

Question 4

In Bitcoin's Proof of Work system, what are miners primarily doing when they are 'mining'?

Accepted Answer

Repeatedly hashing a block header with a changing nonce to find a hash below a target value.

Answer

Bitcoin mining involves repeatedly running the block header through the SHA-256 hash function. Miners vary a number in the block header called a 'nonce' with each hash attempt. The goal is to find a hash output that is numerically lower than the current difficulty target. This process is computationally intensive but easy for other nodes to verify.

Question 5

A new startup begins mining Bitcoin with extremely powerful, next-generation ASIC miners, significantly increasing the total network hash rate. What is the most likely immediate consequence?

Accepted Answer

The average time to find a block will decrease until the next difficulty adjustment.

Answer

When the total network hash rate increases, blocks are found more quickly than the 10-minute target. The system will continue to produce blocks at this faster rate until the next difficulty adjustment period (every 2,016 blocks), at which point the mining difficulty will increase to bring the average block time back to approximately 10 minutes.

(CBP) Certified Bitcoin Professional Practice Test

(CBP) Certified Bitcoin Professional Practice Test

CBP - Certified Bitcoin Professional Bitcoin Mining and Consensus Questions and Answers