CBSE Blockchain System Testing 3

Question 1

Which consensus-layer test verifies that a Byzantine node cannot force honest nodes to accept an invalid block?

Accepted Answer

Byzantine fault tolerance (BFT) test

Answer

BFT testing injects nodes that send conflicting or invalid messages and checks whether honest nodes still reach correct consensus.

Question 2

What is the primary goal of 'state explosion testing' in blockchain smart contract analysis?

Accepted Answer

Identifying all reachable contract states to uncover hidden execution paths

Answer

State explosion testing enumerates all possible contract states to find execution paths that lead to unintended or insecure behavior.

Question 3

During a blockchain node stress test, which metric best indicates the onset of a memory exhaustion denial-of-service condition?

Accepted Answer

Mempool size growing unbounded while node RAM utilization spikes

Answer

An unbounded mempool combined with spiking RAM indicates the node cannot evict or process transactions fast enough, leading to memory exhaustion.

Question 4

A smart contract allows the owner to withdraw all Ether with a single function call with no time-lock. Which test case best captures the associated risk?

Accepted Answer

Test that the owner can drain all funds instantly, simulating a rug-pull scenario

Answer

Simulating an owner-initiated full drain reveals the rug-pull risk that users face when a contract has unrestricted withdrawal authority.

Question 5

In blockchain interoperability testing, what does a 'cross-chain replay attack' test verify?

Accepted Answer

That signed transactions on one chain cannot be rebroadcast and executed on a different chain

Answer

Cross-chain replay attack testing confirms that transaction signatures are chain-specific and cannot be reused on a different network.

(CBSE) Certified Blockchain Security Expert Practice Test

(CBSE) Certified Blockchain Security Expert Practice Test

CBSE Blockchain System Testing 3