CBCP Consensus Mechanisms 5

Question 1

What is 'fork choice rule' and why is it essential in blockchain consensus?

Accepted Answer

An algorithm nodes use to determine which chain branch to follow when multiple valid chains exist

Answer

The fork choice rule provides a deterministic way for all nodes to independently select the same canonical chain from competing branches, maintaining network-wide agreement.

Question 2

In Algorand's consensus, what is a 'committee' and how is it selected?

Accepted Answer

A randomly and privately selected group of validators chosen via VRF proportional to stake

Answer

Algorand uses a VRF-based cryptographic sortition to randomly and privately select a committee each round, with selection probability proportional to each node's stake.

Question 3

What is the CAP theorem's relevance to blockchain consensus design?

Accepted Answer

It states distributed systems cannot simultaneously guarantee Consistency, Availability, and Partition tolerance — forcing design trade-offs

Answer

The CAP theorem forces blockchain designers to choose trade-offs: BFT protocols often favor Consistency and Partition tolerance while sacrificing some Availability during faults.

Question 4

What distinguishes 'synchronous' from 'asynchronous' network models in consensus protocol design?

Accepted Answer

Synchronous models assume bounded message delays; asynchronous models assume no timing guarantees

Answer

Synchronous models allow protocols to rely on known time bounds for message delivery, while asynchronous models (more realistic) cannot assume any timing, making consensus design harder.

Question 5

In Proof of Space (PoSpace) or Proof of Capacity, what resource do validators compete on?

Accepted Answer

Available disk space used to store precomputed cryptographic plots

Answer

Proof of Space requires nodes to pre-fill their disk storage with cryptographic data (plots); nodes with more allocated space have proportionally higher chances of winning block creation rights.

CBCP - Certified Blockchain Professional Practice Test

CBCP - Certified Blockchain Professional Practice Test

CBCP Consensus Mechanisms 5