Blockchain Developer Test 5

Question 1

Which is not popular consensus algorithm in the list

Accepted Answer

Digital workforce

Answer

PBFT (Practical Byzantine Fault Tolerance), Proof-of-Work, and Proof-of-Stake are all well-established and widely used consensus algorithms in blockchain technology. 'Digital workforce' is a term related to human or automated labor, not a mechanism for achieving agreement on the state of a distributed ledger. Therefore, it is not a popular consensus algorithm in the blockchain domain.

Question 2

Why is Blockchain a trusted approach?

Accepted Answer

All of the above

Answer

Blockchain is considered a trusted approach due to its inherent security features, including cryptographic hashing and immutability, which prevent data tampering. Its open-source nature often promotes transparency and compatibility with other applications, fostering wider adoption and scrutiny. The decentralized structure also eliminates single points of failure and the need for intermediaries, collectively building a high degree of trust.

Question 3

Is it possible to modify the data once it is written in a block?

Accepted Answer

No, it’s not possible to do so

Answer

No, it is not possible to modify data once it has been written into a block and that block is added to the blockchain. This immutability is a core security principle of blockchain, enforced by cryptographic links between blocks. Any alteration to a past block would change its hash, invalidating all subsequent blocks and making the tampering immediately detectable and rejected by the network.

Question 4

Is it possible in Blockchain to remove one or more block from the networks?

Accepted Answer

Yes, it can be done

Answer

While individual blocks are immutable, it is technically possible to effectively 'remove' blocks from the *active* chain through certain network events. A hard fork can create a new, incompatible chain that disregards previous blocks, or a 51% attack can allow an attacker to reorganize the blockchain's history, making certain blocks appear to be removed from the longest chain. However, this doesn't erase the data, but rather changes the network's agreed-upon history.

Question 5

What are the common types of records that can be kept on the Blockchains?

Accepted Answer

All of these

Answer

Blockchains are highly versatile distributed ledgers capable of securely and transparently storing a wide array of record types. This includes financial transactions, medical records for enhanced privacy and data sharing, and identity management systems for verifying credentials. Their immutable and decentralized nature makes them suitable for any data requiring high integrity, transparency, and trust across various industries.

Blockchain Practice Test

Blockchain Practice Test

Blockchain Developer Test 5