Merkle Tree-Based Transaction Verification BDC Practice Questions (Page 8)

Questions 36–40

1. 36foundation · easy

   Why does a light client use Merkle proofs instead of downloading the entire block?

   • ATo verify a specific transaction with minimal data, without needing all transactions.
   • BTo determine the order of transactions in the block.
   • CTo decrypt the transaction data without the block's private key.
   • DTo validate the transaction's digital signature without the public key.
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2. 37foundation · easy

   How is a Merkle inclusion proof verified?

   • ABy hashing the transaction and comparing it to the Merkle root directly.
   • BBy checking that the transaction hash appears in the block's transaction list.
   • CBy decrypting the transaction hash with the block's private key.
   • DBy recomputing the root from the transaction hash and the sibling hashes in the path, then comparing it to the known root.
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4. 38foundation · easy

   What is the main efficiency benefit of using Merkle trees for transaction verification in blockchain?

   • AIt allows verification of a transaction using only a logarithmic number of hashes relative to the number of transactions.
   • BIt allows all transactions to be verified in constant time regardless of block size.
   • CIt allows nodes to verify transactions without having the block header.
   • DIt eliminates the need to store transaction data on the blockchain.
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5. 39expert · medium

   A developer is implementing a Merkle proof verification function. The function receives a transaction hash, a Merkle path (list of sibling hashes), and a root. The function must return true if the transaction is in the block. Which implementation detail is critical for correctness?

   • AThe timestamp of the block.
   • BThe number of transactions in the block.
   • CThe order in which the current hash and sibling are concatenated at each step.
   • DThe length of the transaction hash.
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6. 40foundation · easy

   How does the Merkle tree structure the transaction list in a blockchain block?

   • ATransactions are hashed as leaves, and the resulting tree's root is stored in the block header.
   • BTransactions are encrypted and stored in a tree, with the decryption key in the header.
   • CTransactions are sorted and stored in a binary search tree, with the root in the header.
   • DTransactions are stored as a linked list, and the hash of the last transaction is stored in the header.
   Reveal Solution Discussion Select an answer first