Skip to content

CS Professional · Artificial Intelligence, Data Analytics and Cyber Security - Laws and Practice · Internet and Other Technologies

A Pune firm builds a blockchain-based record system for share transfers. A director claims the entries, once validated and chained by hashes, can be edited quietly by the administrator to correct errors. Which assessment is technically correct?

The claim is wrong. Each block contains the previous block's hash, so altering an earlier entry changes its hash and breaks every later link, making tampering evident. Errors are corrected by appending a new correcting entry rather than editing history.

  1. ACorrect, since a permissioned blockchain always lets the administrator alter past blocks without trace
  2. BIncorrect, because altering a past block changes its hash and breaks the chain of later hashes, so corrections are made by appending new entriesCorrect
  3. CCorrect, because hashes are only used for encryption of the data
  4. DIncorrect, because blockchain stores no data about transactions

Explanation

Each block holds the hash of the previous block, so changing an old entry changes its hash and invalidates all subsequent links, making tampering evident. Errors are therefore fixed by adding a correcting transaction. The claim that edits are untraceable ignores this chaining.

Did you get it right without looking?

One question tells you little. A timed set on Internet and Other Technologies shows your real accuracy, how long you take and where you lose marks.

Practise Internet and Other TechnologiesFree diagnostic mock

More Internet and Other Technologies questions