CBP Blockchain and Transaction Mechanics 3

Question 1

What is a Merkle tree used for in a Bitcoin block?

Accepted Answer

Efficiently summarizing and verifying all transactions in a block

Answer

The Merkle tree hashes pairs of transaction IDs up to a single root, allowing efficient proof that a specific transaction is included in a block.

Question 2

What problem does Simplified Payment Verification (SPV) solve for Bitcoin users?

Accepted Answer

It lets lightweight clients verify transactions without downloading the entire blockchain

Answer

SPV lets clients verify a transaction's inclusion in a block using only block headers and a Merkle proof, rather than the full blockchain.

Question 3

In Bitcoin's scripting system, what does the opcode OP_CHECKSIG do?

Accepted Answer

It verifies that a provided signature is valid for the given public key and transaction hash

Answer

OP_CHECKSIG pops a public key and a signature from the stack, verifies the signature against the serialized transaction hash, and pushes TRUE or FALSE.

Question 4

What is the significance of a transaction achieving 6 confirmations in Bitcoin?

Accepted Answer

It is a widely accepted threshold indicating the transaction is extremely difficult to reverse

Answer

Six confirmations is a practical industry standard because reversing 6 blocks would require controlling enormous hashrate, making attacks economically infeasible for typical amounts.

Question 5

Which of the following best describes an orphan block in Bitcoin?

Accepted Answer

A valid block whose parent block is not yet known to the receiving node

Answer

An orphan (or stale) block is a valid block whose predecessor has not yet been received, so it temporarily cannot be attached to the known chain.

(CBP) Certified Bitcoin Professional Practice Test

(CBP) Certified Bitcoin Professional Practice Test

CBP Blockchain and Transaction Mechanics 3