Fundamental Concepts and Working Principles of Blockchain Technology BBLC Practice Questions (Page 11)

Questions 51–55

1. 51foundation · easy

   What does 'immutability' mean in blockchain?

   • AOnce a block is added, it is extremely difficult to change without detection.
   • BData is stored in a centralized database that is backed up daily.
   • CData on the blockchain can be edited by authorized administrators.
   • DAll participants have the same view of the ledger at all times.
   Reveal Solution Discussion Select an answer first
2. 52foundation · easy

   Which scenario is best suited for a consortium blockchain?

   • AA group of banks sharing a common ledger for interbank transactions.
   • BA public cryptocurrency for global payments.
   • CA single company tracking its internal inventory.
   • DA personal ledger for an individual's expenses.
   Reveal Solution Discussion Select an answer first
4. 53expert · hard

   A company is evaluating whether to use a blockchain to store audit logs for regulatory compliance. They are concerned about the 'right to be forgotten' under GDPR, which requires that personal data be erased upon request. Which approach best addresses the conflict between blockchain immutability and GDPR data erasure requirements?

   • AEncrypt the personal data on-chain and discard the encryption key when erasure is requested.
   • BStore personal data off-chain and store only a hash of the data on-chain, allowing the on-chain record to remain while the off-chain data is deleted.
   • CUse a private blockchain with a trusted administrator who can delete blocks when required.
   • DAvoid using blockchain for any data that might be subject to erasure requests.
   Reveal Solution Discussion Select an answer first
5. 54foundation · easy

   What is decentralization in blockchain?

   • AThe use of a central server to store all copies of the ledger.
   • BThe distribution of control and decision-making across multiple nodes rather than a single entity.
   • CThe ability of any user to modify past transactions.
   • DThe process of encrypting data with multiple keys.
   Reveal Solution Discussion Select an answer first
6. 55application · medium

   A logistics company is designing a blockchain-based shipment tracking system. Each shipment event (e.g., departure, arrival) will be recorded as a transaction and grouped into blocks. The CTO wants to ensure that if an attacker modifies a single historical event, the alteration is immediately detectable by any node that later validates the chain. Which property of the block structure is the primary mechanism that provides this detection capability?

   • AEach block stores a copy of all previous transactions, so any modification is detected by comparing the full history stored in the block.
   • BEach block contains a timestamp that is verified against a trusted time authority, so any historical modification is flagged as an invalid timestamp.
   • CEach block is encrypted with the private key of the previous block's miner, so only the original miner can modify it without detection.
   • DEach block stores the cryptographic hash of the previous block's header, creating a linked chain where any change breaks the hash linkage.
   Reveal Solution Discussion Select an answer first