Certified Bitcoin Professional (CBP) — Questions and Answers

Question 1: What distinguishes an ASIC miner from a GPU miner in the context of Bitcoin?

ASICs can mine any cryptocurrency while GPUs are Bitcoin-specific
ASICs are designed solely for SHA-256 hashing and are far more efficient than GPUs (Correct answer)
ASICs use proof-of-stake while GPUs use proof-of-work
GPUs are more energy-efficient than ASICs for Bitcoin mining

Correct answer: ASICs are designed solely for SHA-256 hashing and are far more efficient than GPUs

ASICs (Application-Specific Integrated Circuits) are purpose-built for SHA-256 and achieve orders-of-magnitude better efficiency than GPUs.

Question 2: What Lightning improvement allows a single payment to be split across multiple routes?

AMP (Atomic Multi-Path Payments) (Correct answer)
BIP32
SegWit
Taproot

Correct answer: AMP (Atomic Multi-Path Payments)

Atomic Multi-Path Payments (AMP) allow a single Lightning payment to be split across multiple routes, improving success rates for larger payments.

Question 3: How does the Lightning Network relate to Bitcoin mining and on-chain fees?

Lightning reduces on-chain transaction volume, potentially decreasing fee pressure for miners long-term (Correct answer)
Lightning transactions must be confirmed by miners before they settle
Lightning replaces proof-of-work with payment-channel consensus
Lightning miners receive separate block rewards for routing payments

Correct answer: Lightning reduces on-chain transaction volume, potentially decreasing fee pressure for miners long-term

By moving the majority of small payments off-chain into payment channels, Lightning reduces on-chain congestion, which can lower average transaction fees miners collect per block.

Question 4: What is Bitcoin's role as 'digital gold' in the broader financial ecosystem?

Bitcoin serves as a scarce, non-sovereign store of value similar to gold's role in traditional finance (Correct answer)
Bitcoin can be converted to gold at any time through the blockchain
Bitcoin physically backs gold commodity contracts
Bitcoin replaces gold in industrial manufacturing

Correct answer: Bitcoin serves as a scarce, non-sovereign store of value similar to gold's role in traditional finance

Bitcoin is often compared to gold due to its limited supply, durability, and non-sovereign nature, positioning it as a digital store of value in portfolios.

Question 5: Which consensus rule determines which chain Bitcoin nodes consider valid when two chains of equal length exist?

The chain with the lowest difficulty
The chain created by the oldest node
The chain with the most transactions
The chain with the most accumulated proof-of-work (Correct answer)

Correct answer: The chain with the most accumulated proof-of-work

Bitcoin nodes follow the chain with the greatest cumulative proof-of-work, often called the 'heaviest' chain.

Question 6: The Cantillon Effect describes what economic phenomenon?

The tendency for money to lose value in foreign markets
Wealthy nations accumulate gold at the expense of poorer nations
The lag between interest rate changes and their economic effects
New money entering an economy benefits those who receive it first before prices rise (Correct answer)

Correct answer: New money entering an economy benefits those who receive it first before prices rise

The Cantillon Effect states that newly created money benefits early recipients (like banks and governments) before it causes general price inflation.

Question 7: Which Bitcoin Improvement Proposal introduced the concept of version bits to coordinate multiple soft fork activations simultaneously?

BIP 16
BIP 91
BIP 141
BIP 9 (Correct answer)

Correct answer: BIP 9

BIP 9 introduced version bits signaling, allowing miners to signal readiness for up to 29 soft forks concurrently using bits in the block version field.

Question 8: What are Schnorr signatures, introduced with Taproot?

A signature scheme enabling key aggregation and batch verification (Correct answer)
A wallet recovery protocol
A mining algorithm replacing SHA-256
A new type of Bitcoin address format

Correct answer: A signature scheme enabling key aggregation and batch verification

Schnorr signatures allow multiple signatures to be aggregated into one, enabling more efficient multi-sig transactions and batch verification.

Question 9: What is 'transaction malleability' and which upgrade largely resolved it for Bitcoin?

The ability to redirect outputs; resolved by multisig
The ability to alter a transaction's ID without changing its content; largely resolved by SegWit (Correct answer)
The ability to alter a transaction's amount before confirmation; resolved by Taproot
The ability to reverse confirmed transactions; resolved by Lightning Network

Correct answer: The ability to alter a transaction's ID without changing its content; largely resolved by SegWit

Transaction malleability allowed third parties to alter a transaction's TXID before confirmation; SegWit moved signature data outside the TXID calculation, largely eliminating this.

Question 10: Which property ensures that one unit of money is interchangeable with another unit of the same denomination?

Fungibility (Correct answer)
Acceptability
Durability
Scarcity

Correct answer: Fungibility

Fungibility means each unit of currency is identical and interchangeable with every other unit of the same denomination.

Question 11: What is the primary advantage of using a hardware wallet over a software wallet?

Hardware wallets do not require seed phrase backups
Hardware wallets support more cryptocurrencies
Hardware wallets process transactions faster
Private keys are generated and stored on an isolated device and never exposed to internet-connected systems (Correct answer)

Correct answer: Private keys are generated and stored on an isolated device and never exposed to internet-connected systems

Hardware wallets keep private keys in a secure element isolated from networked devices, so signing happens on the device and keys are never exported.

Question 12: What is 'merge mining'?

Merging two mining pools into a single entity
Running Bitcoin and Litecoin nodes on the same server
Combining multiple ASIC devices into a single mining unit
Mining two or more cryptocurrencies simultaneously using the same proof-of-work (Correct answer)

Correct answer: Mining two or more cryptocurrencies simultaneously using the same proof-of-work

Merge mining allows miners to simultaneously mine Bitcoin and an auxiliary chain like Namecoin with no extra computational cost.

Question 13: What hashing algorithm does Bitcoin use for its proof-of-work mining process?

MD5
SHA-512
Keccak-256
SHA-256 (Correct answer)

Correct answer: SHA-256

Bitcoin uses SHA-256 (Secure Hash Algorithm 256-bit) as the basis for its proof-of-work mining algorithm.

Question 14: What happens when a Bitcoin block is successfully mined?

The network resets
All pending transactions are canceled
The miner is rewarded with new Bitcoin and transaction fees (Correct answer)
The miner receives transaction fees only

Correct answer: The miner is rewarded with new Bitcoin and transaction fees

When a block is mined, it is added to the blockchain, and the miner is rewarded with newly minted Bitcoin plus transaction fees.

Question 15: A Bitcoin user has a 12-word mnemonic seed phrase. What is the primary function of this phrase in relation to cryptographic keys?

It is a human-readable representation of the user's public key.
It serves as a symmetric key to decrypt incoming Bitcoin.
It is used to deterministically generate all private keys in a hierarchical deterministic (HD) wallet. (Correct answer)
It directly encrypts the transaction data on the blockchain.

Correct answer: It is used to deterministically generate all private keys in a hierarchical deterministic (HD) wallet.

A mnemonic seed phrase, as defined by standards like BIP39, is a backup mechanism. It is used as a seed to a deterministic algorithm that can recreate the master private key, and from there, all the public/private key pairs within the wallet. This allows a user to restore their entire wallet on a new device with just the seed phrase.

Question 16: What is the significance of the 'extraNonce' field used by miners?

It encodes the software version used
It extends the nonce search space within the coinbase transaction (Correct answer)
It records the pool's fee percentage
It stores the miner's wallet address

Correct answer: It extends the nonce search space within the coinbase transaction

Since the 32-bit nonce space exhausts quickly, miners use the extraNonce in the coinbase to expand their search space.

Question 17: What is the 'velocity of money'?

The speed at which money is printed by a central bank
The rate at which money changes hands in an economy (Correct answer)
The rate of currency appreciation against foreign currencies
The interest rate at which banks lend to each other

Correct answer: The rate at which money changes hands in an economy

Velocity of money measures how frequently a unit of currency is used to purchase goods and services within a given time period.

Question 18: What is the primary function of Bitcoin's blockchain?

To create new bitcoins
To store transaction data in a secure and decentralized manner (Correct answer)
To regulate Bitcoin prices
To control Bitcoin supply

Correct answer: To store transaction data in a secure and decentralized manner

The blockchain is a decentralized ledger that records all Bitcoin transactions in a secure and immutable way.

Question 19: In the U.S., which agency has claimed jurisdiction over Bitcoin derivatives and futures contracts?

Securities and Exchange Commission (SEC)
Federal Reserve Board (FRB)
Commodity Futures Trading Commission (CFTC) (Correct answer)
Financial Industry Regulatory Authority (FINRA)

Correct answer: Commodity Futures Trading Commission (CFTC)

The CFTC has asserted jurisdiction over Bitcoin as a commodity and regulates Bitcoin-related derivatives and futures contracts.

Question 20: What is required to open a Lightning Network payment channel?

An on-chain Bitcoin transaction to fund the channel (Correct answer)
A mining license
Permission from the Bitcoin Foundation
A KYC verification process

Correct answer: An on-chain Bitcoin transaction to fund the channel

Opening a Lightning channel requires broadcasting an on-chain funding transaction that locks Bitcoin into a multi-signature address.

Question 21: During the 2017 Bitcoin scaling debate, BIP 148 was a proposal for which type of activation?

A UASF to force SegWit activation by August 1, 2017 (Correct answer)
A hard fork to increase block size to 2MB
A miner-activated soft fork for SegWit2x
A soft fork to reduce the block time to 5 minutes

Correct answer: A UASF to force SegWit activation by August 1, 2017

BIP 148 specified that nodes would reject blocks not signaling SegWit support starting August 1, 2017, making it a UASF.

Question 22: What was the primary problem with early paper money (banknotes) issued by private banks in the 1800s?

Paper was too fragile to use as currency
Paper notes could not be divided into smaller amounts
Different banks issued notes that varied in trustworthiness and redemption reliability (Correct answer)
The government taxed paper money at higher rates than coins

Correct answer: Different banks issued notes that varied in trustworthiness and redemption reliability

Private bank notes had varying reliability since each bank's notes were only as good as that bank's reputation and gold reserves, creating confusion and risk.

Question 23: How does the Lightning Network relate to Bitcoin's base layer security?

Lightning is secured by a different set of miners
Lightning uses a separate proof-of-work system
Lightning completely replaces Bitcoin's blockchain security
Lightning inherits Bitcoin's base layer security since channels are settled on-chain (Correct answer)

Correct answer: Lightning inherits Bitcoin's base layer security since channels are settled on-chain

Lightning channels ultimately settle on the Bitcoin blockchain, so the base layer's proof-of-work security underpins all Lightning Network transactions.

Question 24: Which of the following is NOT considered a primary function of money?

Unit of Account
Medium of Exchange
Speculation (Correct answer)
Store of Value

Correct answer: Speculation

The three primary functions of money are: a medium of exchange, a unit of account, and a store of value. Speculation is an activity that can be done with money, but it is not a fundamental function of money itself.

Question 25: What does BIP stand for in Bitcoin development?

Bitcoin Interoperability Program
Blockchain Implementation Package
Bitcoin Investment Protocol
Bitcoin Improvement Proposal (Correct answer)

Correct answer: Bitcoin Improvement Proposal

A BIP (Bitcoin Improvement Proposal) is the formal process for proposing changes or additions to Bitcoin's protocol, similar to RFC documents in internet standards.

Question 26: What is the role of a 'checksum' in Bitcoin address encoding?

The checksum encrypts the address so only the intended recipient can decode it
Checksums in Bitcoin addresses extend the address length to prevent collisions
It adds error-detection bytes to the address so typos or corrupted characters are caught before sending funds (Correct answer)
It is a hash of the private key appended to the address for authentication

Correct answer: It adds error-detection bytes to the address so typos or corrupted characters are caught before sending funds

Bitcoin Base58Check encoding appends 4 checksum bytes (first 4 bytes of double-SHA256) to detect transcription errors before a transaction is broadcast.

Question 27: What is the significance of the 'nonce' field in a Bitcoin block header?

Miners increment it to change the block hash until it meets the difficulty target (Correct answer)
It stores the miner's wallet address for the coinbase reward
It records the number of transactions in the block
It timestamps the block to the nearest second

Correct answer: Miners increment it to change the block hash until it meets the difficulty target

The 32-bit nonce is iterated by miners during proof-of-work to find a block hash below the current difficulty target.

Question 28: When using a hardware wallet with a passphrase, what is the consequence of forgetting the passphrase?

The hardware wallet resets to factory settings automatically
The hardware manufacturer can recover the passphrase
Funds in the passphrase-protected wallet are permanently inaccessible even with the correct seed phrase (Correct answer)
The wallet reverts to using the seed phrase alone

Correct answer: Funds in the passphrase-protected wallet are permanently inaccessible even with the correct seed phrase

The passphrase is not stored anywhere and deterministically modifies key derivation, so without it the correct child keys cannot be derived and funds are irrecoverably lost.

Question 29: What is the 'block reward' in Bitcoin and how does it change over time?

A bonus paid to miners who find blocks faster than the 10-minute target
A reward paid by transaction senders directly to the miner
The newly created bitcoin awarded to the miner of each block; it halves approximately every 4 years (every 210,000 blocks) (Correct answer)
A fixed reward of 6.25 BTC that never changes

Correct answer: The newly created bitcoin awarded to the miner of each block; it halves approximately every 4 years (every 210,000 blocks)

The block subsidy started at 50 BTC and halves every 210,000 blocks, with the total supply approaching but never exceeding 21 million BTC.

Question 30: In the context of BIP39 mnemonic seed phrases, what cryptographic function converts the word list into a binary seed?

RIPEMD-160 hashes each word individually and concatenates the results into a seed
The mnemonic words are XOR'd together using AES-256 to form the binary seed
SHA-256 applied directly to the word list to produce a 256-bit wallet seed
PBKDF2 with HMAC-SHA512, applying 2048 iterations to stretch the mnemonic into a 512-bit seed (Correct answer)

Correct answer: PBKDF2 with HMAC-SHA512, applying 2048 iterations to stretch the mnemonic into a 512-bit seed

BIP39 uses PBKDF2-HMAC-SHA512 with 2048 iterations and an optional passphrase salt to derive the 512-bit master seed from the mnemonic.

Question 31: A user wants to pay for coffee using Bitcoin without waiting for block confirmation. Which solution is most appropriate?

Lightning Network payment channel (Correct answer)
On-chain Bitcoin transaction with 1 confirmation
Bitcoin paper wallet transfer
Multi-signature Bitcoin transaction

Correct answer: Lightning Network payment channel

Lightning Network payments settle instantly off-chain, making them ideal for small, time-sensitive purchases like coffee.

Question 32: What is the purpose of a Bitcoin address compared to a public key?

A Bitcoin address is a hashed, encoded form of the public key for shorter, safer sharing (Correct answer)
A Bitcoin address is identical to the public key
A Bitcoin address is derived from the private key directly
A Bitcoin address is a randomly generated identifier unrelated to cryptographic keys

Correct answer: A Bitcoin address is a hashed, encoded form of the public key for shorter, safer sharing

A Bitcoin address is produced by applying SHA-256 and RIPEMD-160 to the public key, then Base58Check encoding, providing a shorter and more error-resistant identifier.

Question 33: What does KYC stand for and why do regulated exchanges require it?

Know Your Counterparty — to assess trading risk exposure
Keep Your Credentials — to secure login information
Know Your Cryptocurrency — to classify assets by type
Know Your Customer — to verify user identity and comply with AML regulations (Correct answer)

Correct answer: Know Your Customer — to verify user identity and comply with AML regulations

KYC (Know Your Customer) requires exchanges to verify user identities using government-issued IDs, fulfilling AML obligations by ensuring they know who they are serving.

Question 34: What is the purpose of Bitcoin's 'mempool'?

A pool of mining nodes competing for the next block reward
A database of all confirmed transactions in the blockchain
A reserve of bitcoins held by the Bitcoin Foundation
A holding area where unconfirmed transactions wait until miners select and include them in a block (Correct answer)

Correct answer: A holding area where unconfirmed transactions wait until miners select and include them in a block

The mempool (memory pool) is each node's local set of valid, unconfirmed transactions that miners draw from when constructing new blocks.

Question 35: In asymmetric cryptography (also known as public-key cryptography), which key is kept secret and which is shared?

The public key is kept secret, and the private key is shared.
Both the public and private keys are shared.
The private key is kept secret, and the public key is shared. (Correct answer)
Both the public and private keys are kept secret.

Correct answer: The private key is kept secret, and the public key is shared.

The core principle of asymmetric cryptography is the use of a key pair: a private key, which must be kept secret by the owner, and a public key, which can be freely distributed. Data encrypted with the public key can only be decrypted by the corresponding private key, and a signature created with the private key can be verified with the public key.

Question 36: Which payout scheme pays miners a fixed amount per valid share regardless of when a block is found?

Solo mining
PPLNS (Pay Per Last N Shares)
Proportional
PPS (Pay Per Share) (Correct answer)

Correct answer: PPS (Pay Per Share)

PPS pays a fixed, expected-value amount per share submitted, transferring variance risk from the miner to the pool operator.

Question 37: What is 'channel rebalancing' in the Lightning Network?

Resetting a wallet's seed phrase
Redistributing funds across channels to maintain sending and receiving capacity (Correct answer)
Reallocating mining hashrate
Adjusting Bitcoin block sizes

Correct answer: Redistributing funds across channels to maintain sending and receiving capacity

Channel rebalancing moves liquidity within or across channels so a node can maintain both inbound and outbound capacity for optimal routing.

Question 38: How does routing Bitcoin transactions over the Tor network improve privacy?

It hides the user's IP address when broadcasting transactions, preventing network-level surveillance of transaction origin (Correct answer)
It prevents wallet addresses from being indexed by search engines
It encrypts the Bitcoin blockchain data stored on the user's local node
It anonymizes the miner's identity when they claim a block reward

Correct answer: It hides the user's IP address when broadcasting transactions, preventing network-level surveillance of transaction origin

When transactions are broadcast over Tor, the user's real IP address is masked, making it harder for network observers to link broadcasted transactions to specific users.

Question 39: What does 'computational infeasibility' mean in the context of Bitcoin cryptographic security?

Breaking the cryptography would require more computing resources or time than is practically available, even with current hardware (Correct answer)
The cryptographic algorithms are impossible to run on standard computers due to their complexity
It refers to encrypted data that becomes permanently unreadable if the private key is lost
Computational infeasibility means only Bitcoin miners have the hardware to perform cryptographic operations

Correct answer: Breaking the cryptography would require more computing resources or time than is practically available, even with current hardware

Computational infeasibility means the attack would take longer than the age of the universe or require more energy than exists, making it practically impossible.

Question 40: In Bitcoin script, what does OP_RETURN do?

Marks an output as provably unspendable and can embed up to 80 bytes of arbitrary data (Correct answer)
Signals the miner to return the fee if the transaction is delayed
Terminates script execution with a success flag
Returns change to the sender automatically

Correct answer: Marks an output as provably unspendable and can embed up to 80 bytes of arbitrary data

OP_RETURN immediately marks the output as unspendable and allows embedding small arbitrary data on-chain; nodes can prune these from the UTXO set.

Question 41: What role do private keys play in Bitcoin transactions?

To encrypt messages on the network
To sign transactions and prove ownership of Bitcoin (Correct answer)
To verify other users' transactions
To generate new bitcoins

Correct answer: To sign transactions and prove ownership of Bitcoin

Private keys are used to sign transactions, proving ownership and enabling the spending of Bitcoin securely.

Question 42: The concept of a 'circular economy' in the context of Bitcoin refers to a system where:

Individuals and businesses earn, spend, and save in Bitcoin without needing to convert it to fiat currency. (Correct answer)
Miners sell newly minted bitcoins to pay for electricity, and the buyers hold them as a long-term investment.
Bitcoin is primarily used for speculative trading on exchanges to generate fiat profits.
Bitcoin is wrapped onto other blockchains for DeFi applications and then brought back to the main chain.

Correct answer: Individuals and businesses earn, spend, and save in Bitcoin without needing to convert it to fiat currency.

A Bitcoin circular economy is a self-sustaining ecosystem where Bitcoin is used as the primary medium of exchange. [2, 14] People earn their salary in bitcoin, use it to buy goods and services, and merchants use it to pay suppliers, all within the Bitcoin economy, reducing the need to exit to fiat currency. [5]

Question 43: What is a 'submarine swap' in the Lightning Network?

A protocol for mining in underwater data centers
An atomic swap between on-chain Bitcoin and Lightning Network Bitcoin (Correct answer)
A physical exchange of Bitcoin at sea
A method to anonymize Bitcoin transactions

Correct answer: An atomic swap between on-chain Bitcoin and Lightning Network Bitcoin

A submarine swap is an atomic exchange that allows converting between on-chain Bitcoin and Lightning Network Bitcoin without trusting a third party.

Question 44: In a Bitcoin wallet, what does a BIP39 mnemonic seed phrase represent?

A checksum of the wallet's transaction history
The private key in Base58Check format
A list of wallet addresses
An entropy value encoded as human-readable words used to derive a hierarchical deterministic wallet (Correct answer)

Correct answer: An entropy value encoded as human-readable words used to derive a hierarchical deterministic wallet

BIP39 encodes entropy as 12–24 human-readable words that serve as the root seed for deriving all keys in an HD wallet.

Question 45: Why is Bitcoin considered a hedge against inflation?

Because Bitcoin is controlled by a central bank
Because it has a fixed supply and cannot be inflated (Correct answer)
Because Bitcoin prices never fluctuate
Because it is pegged to gold reserves

Correct answer: Because it has a fixed supply and cannot be inflated

Bitcoin's fixed supply of 21 million coins prevents inflationary devaluation, unlike fiat currencies that can be printed indefinitely.

Question 46: What is 'commodity money'?

Digital tokens representing real assets
Money backed by government decree
Banknotes issued by central banks
Money with intrinsic value made from a valuable commodity (Correct answer)

Correct answer: Money with intrinsic value made from a valuable commodity

Commodity money has intrinsic value because it is made from a substance that has value in itself, such as gold or silver coins.

Question 47: What is the purpose of OP_RETURN in Bitcoin Script?

To trigger smart contract execution
To embed arbitrary data in an unspendable transaction output (Correct answer)
To return change to the sender's wallet
To return funds to the sender

Correct answer: To embed arbitrary data in an unspendable transaction output

OP_RETURN marks a transaction output as unspendable and allows up to 80 bytes of arbitrary data to be recorded immutably on the blockchain.

Question 48: What is the role of the Merkle root stored in a Bitcoin block header?

It records the total fee amount paid to the miner
It contains the difficulty target encoded in compact form
It is a compact cryptographic commitment to all transactions in the block (Correct answer)
It stores the hash of the previous block for chain linking

Correct answer: It is a compact cryptographic commitment to all transactions in the block

The Merkle root is the root hash of a binary Merkle tree built from all transaction IDs, allowing efficient proof that any transaction is included in the block.

Question 49: What is a PSBT (Partially Signed Bitcoin Transaction)?

A transaction broadcast to only half the network nodes
A compressed transaction format for mobile wallets
A transaction with only one input partially funded
A transaction format allowing multiple parties to collaboratively sign before finalization (Correct answer)

Correct answer: A transaction format allowing multiple parties to collaboratively sign before finalization

PSBT (BIP-174) defines a portable format for transactions that can be passed between wallets for signing by multiple parties before being finalized and broadcast.

Question 50: Which property of money ensures that one unit of the currency is interchangeable with another unit of the same value?

Divisibility
Durability
Fungibility (Correct answer)
Portability

Correct answer: Fungibility

Fungibility means that individual units of a commodity or currency are interchangeable and essentially indistinguishable from one another. For example, one dollar is treated the same as any other dollar. This uniformity is a key property of good money.

Question 51: Which of the following best describes a 'selfish mining' attack?

A miner withholds found blocks to gain a disproportionate share of rewards (Correct answer)
A miner colludes with exchanges to manipulate the bitcoin price
A miner submits invalid blocks to disrupt the network
A miner refuses to relay transactions to neighboring peers

Correct answer: A miner withholds found blocks to gain a disproportionate share of rewards

In selfish mining, a pool secretly mines on its private chain and strategically releases blocks to waste competing miners' work, gaining more than its fair share of rewards.

Question 52: What is the Dandelion protocol (BIP156) designed to do?

Anonymously mine Bitcoin blocks without revealing the miner's IP address
Generate untraceable Bitcoin addresses using zero-knowledge proofs
Propagate transactions through a random path of nodes before broad broadcast, obscuring the originating node (Correct answer)
Hide wallet balances from other nodes on the network

Correct answer: Propagate transactions through a random path of nodes before broad broadcast, obscuring the originating node

Dandelion propagates transactions in a 'stem' phase through a few nodes before 'fluff' (normal broadcast), making it significantly harder to identify the originating node.

Question 53: What is 'M1' in the context of money supply measurements?

The narrowest measure of money, including cash and demand deposits (Correct answer)
The broadest measure including all financial instruments
Total national debt including bonds
Money held in retirement accounts

Correct answer: The narrowest measure of money, including cash and demand deposits

M1 is the narrowest money supply measure, comprising physical currency in circulation plus demand deposits (checking accounts).

Question 54: What does it mean for a hash function to be 'collision-resistant'?

Collision resistance means the hash output length never changes
It is computationally infeasible to find two different inputs that produce the same hash output (Correct answer)
It means the function cannot be run more than once on the same data
The hash function never produces the same output twice for any input

Correct answer: It is computationally infeasible to find two different inputs that produce the same hash output

Collision resistance means that finding two distinct inputs x and y where H(x) = H(y) is computationally infeasible.

Question 55: What is the primary purpose of SegWit (Segregated Witness) for Bitcoin commerce?

To separate signature data from transaction data, reducing transaction size and fees (Correct answer)
To enable anonymous transactions on the Bitcoin network
To replace proof-of-work mining with proof-of-stake
To double the Bitcoin supply cap to 42 million coins

Correct answer: To separate signature data from transaction data, reducing transaction size and fees

SegWit removes signature data from the transaction block space calculation, effectively increasing throughput and reducing fees for commerce.

Question 56: What is the purpose of the Bitcoin mempool?

A pool of available mining hardware
A reserve of Bitcoin held by the network for miner rewards
A database of all confirmed Bitcoin transactions
A temporary holding area for unconfirmed transactions waiting to be included in a block (Correct answer)

Correct answer: A temporary holding area for unconfirmed transactions waiting to be included in a block

The mempool (memory pool) is where unconfirmed transactions wait until a miner selects them for inclusion in the next block.

Question 57: What is the significance of the 'witness discount' introduced by SegWit?

The witness discount halves the mining difficulty for SegWit blocks
Witness data is counted at one-quarter the weight of non-witness data, reducing the effective size of SegWit transactions (Correct answer)
SegWit transactions skip the signature verification step
Miners receive bonus fees for including SegWit transactions

Correct answer: Witness data is counted at one-quarter the weight of non-witness data, reducing the effective size of SegWit transactions

SegWit introduced block weight (replacing byte size), with witness data counted at 1 weight unit per byte versus 4 for non-witness data, making SegWit transactions cheaper.

Question 58: What is the role of a Bitcoin exchange in the ecosystem?

To issue Bitcoin debit cards
To provide a marketplace where Bitcoin can be bought and sold for fiat or other assets (Correct answer)
To create new Bitcoin through mining
To act as a node that validates transactions

Correct answer: To provide a marketplace where Bitcoin can be bought and sold for fiat or other assets

Bitcoin exchanges provide liquidity and price discovery by matching buyers and sellers of Bitcoin against fiat currencies or other assets.

Question 59: In the context of U.S. tax law, how does the IRS classify Bitcoin?

Property subject to capital gains tax (Correct answer)
A commodity exempt from income tax
Legal tender treated like U.S. dollars
Foreign currency subject to currency gain/loss rules

Correct answer: Property subject to capital gains tax

The IRS classifies Bitcoin as property, meaning capital gains rules apply when it is sold, exchanged, or used to purchase goods.

Question 60: Which characteristic makes gold particularly well-suited as a store of value compared to most commodities?

Gold has high industrial demand that guarantees its value
Gold can be easily subdivided with common household tools
Gold prices are fixed by international governments
Gold is virtually indestructible and does not corrode or degrade over time (Correct answer)

Correct answer: Gold is virtually indestructible and does not corrode or degrade over time

Gold's exceptional durability — it doesn't rust, tarnish, or degrade — makes it uniquely suited as a long-term store of value across centuries.

Question 61: What happens to the purchasing power of money during a period of deflation?

It increases as prices fall (Correct answer)
It fluctuates based on interest rates only
It decreases as prices rise
It remains constant regardless of price changes

Correct answer: It increases as prices fall

During deflation, falling price levels mean each unit of currency can buy more goods and services, increasing its purchasing power.

Question 62: What is the relationship between hashrate and difficulty in Bitcoin?

Difficulty decreases as hashrate increases to keep block times constant
Difficulty is fixed and hashrate adjusts to match it
Hashrate and difficulty are independent variables
Difficulty increases as hashrate increases to maintain the ~10-minute block interval (Correct answer)

Correct answer: Difficulty increases as hashrate increases to maintain the ~10-minute block interval

Every 2,016 blocks, the protocol raises difficulty if blocks were found faster than 10 minutes, keeping average block time constant as global hashrate grows.

Question 63: Which ancient trade good commonly served as commodity money in many early African and Asian societies?

Cowrie shells (Correct answer)
Wooden beads
Cotton
Ceramic tiles

Correct answer: Cowrie shells

Cowrie shells were widely used as currency across Africa, South Asia, and East Asia for thousands of years due to their durability and portability.

Question 64: A new soft fork upgrade is scheduled to activate on the Bitcoin network. As an operator of a non-mining full node, what is the primary consequence of choosing NOT to upgrade your software?

Your node will continue to operate but will have a less secure or complete view of the blockchain's state, as it cannot fully validate the new rules. (Correct answer)
Your node will be banned from the network and will stop receiving any new blocks.
Your node will automatically reject all transactions, both old and new, until it is upgraded.
Your node will cause a hard fork because it is enforcing the old rules.

Correct answer: Your node will continue to operate but will have a less secure or complete view of the blockchain's state, as it cannot fully validate the new rules.

Because a soft fork is backward-compatible, a non-upgraded node will still see new blocks created under the new rules as valid and will continue to sync with the network. [2] However, it will not be able to enforce the new, tighter rules itself. It relies on the upgraded majority of miners to enforce them correctly, thus reducing its own validation security and becoming, in a sense, a less-than-full node regarding the new features. [11, 20]

Question 65: Which type of Bitcoin wallet is most vulnerable to theft and hacking?

Multi-signature cold storage
Hardware wallet
Hot wallet connected to the internet (Correct answer)
Paper wallet stored in a safe

Correct answer: Hot wallet connected to the internet

Hot wallets remain connected to the internet, exposing private keys to malware, phishing, and remote attacks.

Question 66: What monetary system involves two metals, typically gold and silver, serving as legal tender at a fixed exchange ratio?

Fiat standard
Managed float
Bimetallism (Correct answer)
Monometallism

Correct answer: Bimetallism

Bimetallism is a monetary system that uses two metals (gold and silver) as the basis for currency, both accepted as legal tender.

Question 67: What penalty mechanism deters cheating in Lightning Network channel closures?

The honest party can claim all channel funds if the other broadcasts an old state (Correct answer)
The cheating party's node is banned from the network
Miners blacklist the cheater's address
A fine paid to the Bitcoin Foundation

Correct answer: The honest party can claim all channel funds if the other broadcasts an old state

If a party broadcasts an outdated channel state to cheat, the other party can use a 'justice transaction' to claim all the channel's funds as a penalty.

Question 68: What does SegWit (Segregated Witness) separate from Bitcoin transactions?

Public keys from private keys
The witness data (signatures) from the transaction data (Correct answer)
Mining fees from block rewards
The sender's address from the receiver's address

Correct answer: The witness data (signatures) from the transaction data

SegWit separates signature (witness) data from transaction data, fixing transaction malleability and effectively increasing block capacity.

Question 69: What is 'wipe-out risk' in the context of a soft fork?

The chance that wallet software deletes user keys after the upgrade
The possibility that all pre-fork UTXOs become unspendable
The risk that a minority miner chain is completely orphaned by the majority chain enforcing new rules (Correct answer)
The risk that miners will erase transaction history during a soft fork

Correct answer: The risk that a minority miner chain is completely orphaned by the majority chain enforcing new rules

In a soft fork, old-rule blocks produced by non-upgraded miners are invalid to upgraded nodes and will be orphaned, 'wiping out' that chain.

Question 70: Which script type is associated with Pay-to-Witness-Public-Key-Hash (P2WPKH) native SegWit addresses?

P2SH
P2PKH
P2PK
Bech32 (Correct answer)

Correct answer: Bech32

Native SegWit P2WPKH addresses use the Bech32 encoding format, identifiable by the 'bc1q' prefix on mainnet.

Question 71: What does KYC (Know Your Customer) require Bitcoin businesses to do?

Provide customers with hardware wallets
Verify the identity of their users to comply with anti-money laundering laws (Correct answer)
Offer customer loyalty rewards in Bitcoin
Mine Bitcoin on behalf of customers

Correct answer: Verify the identity of their users to comply with anti-money laundering laws

KYC regulations require Bitcoin exchanges and businesses to collect and verify customer identity documents to prevent money laundering and fraud.

Question 72: What is 'address reuse' and why does it reduce privacy?

Using the same wallet software version; it creates identifiable patterns in the mempool
Reusing nonce values in signatures; it exposes private keys
Sending to the same Bitcoin address multiple times; it links all transactions to a single identity on the public blockchain (Correct answer)
Recycling old unused addresses; it causes double-spend risks

Correct answer: Sending to the same Bitcoin address multiple times; it links all transactions to a single identity on the public blockchain

Reusing addresses allows blockchain analysts to cluster all transactions involving that address, linking them to a single entity and reducing financial privacy.

Question 73: What is PayJoin (P2EP) in Bitcoin?

A technique where the recipient also contributes an input, breaking the common input ownership heuristic (Correct answer)
A payment protocol that splits a transaction into equal parts for privacy
A method of paying Bitcoin transaction fees via a completely separate transaction
A Lightning Network feature for routing private channel payments

Correct answer: A technique where the recipient also contributes an input, breaking the common input ownership heuristic

In PayJoin, the recipient adds their own UTXO as an input, which breaks the assumption that all inputs belong to a single sender, confusing blockchain analysts.

Question 74: What does the 'merkle root' in a block header represent?

A single hash summarizing all transactions in the block (Correct answer)
The coinbase transaction hash
The miner's public key
The hash of the previous block

Correct answer: A single hash summarizing all transactions in the block

The merkle root is the root hash of a binary hash tree built from all transaction IDs in the block.

Question 75: What is MAST (Merklized Abstract Syntax Tree) in Bitcoin?

A data structure for storing blockchain headers
A way to commit to multiple script conditions while only revealing the executed branch (Correct answer)
A mining algorithm for generating new blocks
A method to compress wallet seed phrases

Correct answer: A way to commit to multiple script conditions while only revealing the executed branch

MAST allows Bitcoin transactions to commit to many possible spending conditions but only reveal and execute the specific condition used, improving privacy and reducing data.

Certified Bitcoin Professional (CBP)

The CBP certification, issued by the CryptoCurrency Certification Consortium (C4), validates professional working knowledge across 33 Bitcoin topics spanning six domains including cryptography, mining, wallets, and the Bitcoin protocol.

Questions

20 min

Time Limit

70%

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