Bitcoin Blockchain Architecture and Network Transactions BFC Practice Questions (Page 7)

Questions 31–35

1. 31expert · hard

   A journalist is investigating a bitcoin transaction and wants to determine the identity of the sender. They have the transaction ID and the recipient's address. Which approach is most likely to reveal the sender's identity?

   • AContact the recipient and ask for the sender's identity.
   • BAnalyze the transaction graph to cluster addresses and correlate with known exchange withdrawal records.
   • CQuery the blockchain for the sender's IP address, which is stored in the transaction.
   • DUse a block explorer to find the sender's public key, which is included in the transaction.
   Reveal Solution Discussion Select an answer first
2. 32application · medium

   A user submits a Bitcoin transaction with a very low fee. After 30 minutes, the transaction is still in the mempool and has not been confirmed. What is the most likely reason?

   • AThe transaction is being verified by a full node before it can be broadcast.
   • BThe transaction is waiting for the next difficulty adjustment to be processed.
   • CThe transaction was rejected by the network because the fee is below the minimum relay fee.
   • DMiners are prioritizing transactions with higher fee rates, so the low-fee transaction waits.
   Reveal Solution Discussion Select an answer first
4. 33application · medium

   A new miner wants to join a mining pool. The pool operator explains that the miner will receive a share of the block reward. What is the primary reason mining pools exist?

   • ATo combine hashing power so participants receive more consistent payouts than solo mining.
   • BTo reduce the difficulty of mining for individual miners.
   • CTo allow miners to avoid paying transaction fees.
   • DTo increase the block reward by pooling transaction fees.
   Reveal Solution Discussion Select an answer first
5. 34foundation · easy

   How does the UTXO model help prevent double-spending in Bitcoin?

   • ABy encrypting each transaction with a unique key
   • BBy requiring every transaction to be approved by a central authority
   • CBy limiting the number of transactions per block
   • DBy ensuring that each UTXO can only be spent once, as nodes reject transactions that reference already-spent outputs
   Reveal Solution Discussion Select an answer first
6. 35expert · hard

   A journalist receives a Bitcoin donation and wants to protect their identity from sophisticated blockchain analysis. They plan to use a new address for each donation and route funds through a mixing service. Which additional measure would most effectively reduce traceability?

   • AWait for the mempool to clear before broadcasting.
   • BUse a coinjoin transaction that combines inputs from multiple users to break the transaction graph.
   • CUse a hardware wallet to store the private keys.
   • DBroadcast the transaction through a public Wi-Fi network.
   Reveal Solution Discussion Select an answer first