Practice Test Geeks(CBP) Certified Bitcoin Professional Practice Test
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Bitcoin Basics and Cryptography Flashcards

7 cards from real CBP practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Bitcoin Basics and Cryptography flashcards as text

  1. What is the 'genesis block' in Bitcoin?

    Answer: The very first block (block #0) mined by Satoshi Nakamoto on January 3, 2009, which launched the Bitcoin blockchain

    Block 0, the genesis block, was hard-coded into the Bitcoin software and contains a famous embedded message referencing a Times headline about bank bailouts.

  2. How does Segregated Witness (SegWit) change Bitcoin transaction structure?

    Answer: It moves signature (witness) data outside the traditional transaction structure, reducing effective transaction size and fixing transaction malleability

    SegWit separates witness data (signatures) from transaction data, enabling more transactions per block and eliminating transaction malleability.

  3. What is a Bitcoin private key at its most fundamental level?

    Answer: A randomly generated 256-bit integer that must remain secret and is used to sign transactions

    A Bitcoin private key is a random 256-bit number; its secrecy is paramount since anyone with it can spend the associated bitcoins.

  4. What does 'transaction malleability' refer to in Bitcoin?

    Answer: The ability of third parties to alter a transaction's txid without invalidating the signature, before confirmation

    Transaction malleability allowed altering non-signed fields (like the scriptSig) to change the transaction hash, causing problems for systems that tracked txids before confirmation.

  5. What is the purpose of a BIP39 mnemonic seed phrase?

    Answer: To encode a wallet's master seed as a human-readable sequence of words that can be used for backup and recovery

    BIP39 maps 128-256 bits of entropy to a wordlist (typically 12 or 24 words) that encodes a master seed, allowing full HD wallet recovery.

  6. In Bitcoin's ECDSA signature scheme, what information does a signature prove?

    Answer: That the signer possesses the private key corresponding to the public key, without revealing the private key itself

    ECDSA signatures prove knowledge of the private key through a mathematical relationship with the public key, enabling trustless authorization without key disclosure.

  7. What is the 'block reward' in Bitcoin and how does it change over time?

    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.