Mining and Transaction Lifecycle Flashcards

What is the primary role of a 'full node' in a cryptocurrency network?

Answer: To independently validate and relay every transaction and block

Full nodes download and independently verify the entire blockchain, enforcing consensus rules without trusting any third party.

What triggers the automatic adjustment of Bitcoin's mining difficulty?

Answer: Every 2,016 blocks to target a 10-minute average block time

Bitcoin adjusts difficulty every 2,016 blocks (approximately every two weeks) to maintain an average block interval of 10 minutes.

In a UTXO-based blockchain like Bitcoin, what must a sender prove to spend funds?

Answer: They know the private key corresponding to the UTXO's locking script

To spend a UTXO, the sender must provide a valid digital signature proving ownership of the private key that matches the UTXO's public key hash.

What is 'merge mining'?

Answer: Mining two different cryptocurrencies simultaneously using the same proof-of-work

Merge mining (AuxPoW) allows miners to mine a parent chain and a child chain simultaneously without extra computational work.

What is the significance of 6 confirmations in Bitcoin?

Answer: It is the threshold at which a transaction is considered practically irreversible

Six confirmations means six blocks have been added on top of the block containing a transaction, making a double-spend attack statistically impractical.

What is the function of a 'coinbase transaction' in a Bitcoin block?

Answer: It is the first transaction in a block that rewards the miner with newly created coins and fees

The coinbase transaction is a special first transaction in each block that creates new Bitcoin and awards it, along with collected fees, to the winning miner.

Which attack requires an entity to control more than 50% of a network's hash rate?

Answer: 51% attack

A 51% attack requires majority hash rate control, enabling the attacker to reorganize recent blocks and potentially double-spend transactions.