Fundamental Concepts and Working Principles of Blockchain Technology BFC Practice Questions (Page 7)

Questions 31–35

1. 31application · medium

   A group of 20 retail banks is forming a shared KYC (Know Your Customer) verification network. They want to maintain control over who can join and read the data, but they also want to avoid a single bank having ultimate authority. Which blockchain type should they choose?

   • APublic blockchain
   • BConsortium blockchain
   • CCentralized database with blockchain-like audit logs
   • DPrivate blockchain operated by one of the banks
   Reveal Solution Discussion Select an answer first
2. 32application · medium

   A hospital network wants to share patient consent records with multiple clinics while ensuring that each clinic can verify the records have not been altered. They are considering a distributed ledger. What is a key advantage of a distributed ledger over a centralized database for this use case?

   • AA distributed ledger is always faster than a centralized database for read operations.
   • BA distributed ledger automatically encrypts all data, making it unreadable to unauthorized parties.
   • CA distributed ledger requires less storage space than a centralized database.
   • DA distributed ledger provides each clinic with a synchronized copy of the ledger, enabling independent verification of data integrity.
   Reveal Solution Discussion Select an answer first
4. 33foundation · easy

   What is the primary role of smart contracts in automating agreements?

   • ATo execute the terms of an agreement automatically when predefined conditions are met
   • BTo store encrypted copies of legal contracts on the blockchain
   • CTo provide legal advice to parties entering into an agreement
   • DTo replace all traditional legal systems with code
   Reveal Solution Discussion Select an answer first
5. 34expert · hard

   A blockchain developer is debugging a smart contract that stores a hash of a document on-chain. The contract currently stores only the document's SHA-256 hash. A user claims that the document was tampered with, but the hash matches the original. What is the most likely reason the hash still matches?

   • ASHA-256 is a broken algorithm and can be reversed to produce the original document.
   • BThe hash was stored in a block that was later modified by a 51% attack.
   • CThe smart contract stored the hash in a variable that is not part of the blockchain's immutable state.
   • DThe hash was computed over a different version of the document than the one the user is comparing.
   Reveal Solution Discussion Select an answer first
6. 35foundation · easy

   What is typically included in a block's header in a blockchain?

   • AThe consensus algorithm used to validate the block
   • BThe full list of transactions and their digital signatures
   • CThe public keys of all network participants
   • DTimestamp, nonce, and the hash of the previous block
   Reveal Solution Discussion Select an answer first