Skip to content

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

A logistics firm in Pune records shipment events on a blockchain. An employee wants to secretly change the temperature entry in an old block. Why would this change be detected by the network?

The change is detected because each block carries the hash of the preceding block. Altering an old entry changes that block's hash, which no longer matches the reference in the next block, and other nodes holding unchanged copies can see the inconsistency.

  1. AEach block contains the hash of the previous block, so altering one block changes its hash and breaks the chain of links in later blocksCorrect
  2. BBlockchain stores data only in one central server that logs all edits
  3. CThe change would be encrypted automatically and made unreadable
  4. DSmart contracts delete any block that is edited

Explanation

Every block stores the previous block's hash. Changing data in an old block changes its hash, so the next block's stored reference no longer matches, and the mismatch is visible to nodes holding other copies. Blockchain is not a single central server, so the second option is wrong.

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