Bitcoin Blockchain Architecture BBLC Practice Questions (Page 1)

Questions 1–5

1. 1application · medium

   A user wants to receive Bitcoin from a friend. The user has a wallet that generates a new address for each transaction. Which statement correctly describes the relationship between the user's public key, address, and private key?

   • AThe address is derived from the public key via hashing, and the private key is used to sign transactions that spend funds sent to that address.
   • BThe private key is stored on the blockchain, and the address is used to look it up when spending.
   • CThe address is the same as the public key, and the private key is used to encrypt the transaction for the recipient.
   • DThe public key is derived from the address, and the private key is used to generate the public key.
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2. 2foundation · easy

   In the Bitcoin network, what is the primary function of the blockchain?

   • ATo record all transactions in a public, chronological, and immutable ledger
   • BTo store the private keys of all users
   • CTo execute smart contracts automatically
   • DTo provide a decentralized domain name system
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4. 3expert · hard

   A mining company is deciding whether to mine Bitcoin or Bitcoin Cash. Both use the same SHA-256 algorithm. The company has access to cheap electricity and a large number of ASIC miners. Which factor should the company primarily consider when choosing between the two networks?

   • AThe number of developers on each project, because more developers guarantee higher coin value.
   • BThe block size limit, because larger blocks always mean higher transaction fees.
   • CThe age of the coin, because older coins are always more profitable to mine.
   • DThe current difficulty and total hash rate of each network, because they determine the expected time and cost to find a block.
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5. 4application · medium

   A financial auditor is reviewing a Bitcoin wallet implementation for a client. The client wants to ensure that only the wallet owner can spend the bitcoins, while still allowing anyone to verify that a transaction was signed by the owner. Which key management approach achieves this?

   • AKeep both the private key and public key secret and only share the address.
   • BUse the same key for both signing and encryption, and share it only with trusted third parties.
   • CKeep the private key secret and share the public key and address publicly.
   • DKeep the public key secret and share the private key publicly.
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6. 5expert · hard

   A developer proposes a protocol change that would increase Bitcoin's block size limit from 1 MB to 2 MB. The change is backward-incompatible: old nodes would reject the larger blocks. The developer wants to deploy the change without creating a permanent split in the network. Which approach best describes a soft fork that could achieve this?

   • AIncrease the block size to 2 MB and require all nodes to upgrade; old nodes that do not upgrade will follow the old chain, creating a permanent split.
   • BUse a segregated witness (SegWit) style change that makes the new 2 MB blocks appear as valid 1 MB blocks to old nodes by moving some data outside the block weight calculation.
   • CChange the difficulty adjustment algorithm to produce smaller blocks, which old nodes will accept as valid.
   • DImpose a new rule that blocks must be smaller than 1 MB, which old nodes already accept, while new nodes enforce the stricter rule; this is backward-compatible and does not split the chain.
   Reveal Solution Discussion Select an answer first