CBE Blockchain Interoperability and Scalability 2

Question 1

What is the Lightning Network's approach to scaling Bitcoin transactions?

Accepted Answer

Payment channels that allow off-chain bilateral transactions settled on-chain only when channels close

Answer

The Lightning Network creates peer-to-peer payment channels where parties transact off-chain; only the opening and closing transactions are recorded on the Bitcoin blockchain.

Question 2

In Polkadot's architecture, what role does the Relay Chain play?

Accepted Answer

It provides shared security and consensus for all connected parachains

Answer

Polkadot's Relay Chain is the central chain that coordinates consensus and security, while parachains handle application-specific logic and connect via slots.

Question 3

What is a 'wrapped token' in the context of blockchain interoperability?

Accepted Answer

A tokenized version of an asset from one blockchain pegged 1:1 and usable on another blockchain

Answer

Wrapped tokens (e.g., WBTC) lock the original asset in a custodial contract and mint an equivalent ERC-20 token on Ethereum, enabling cross-chain liquidity.

Question 4

What problem does the 'blockchain trilemma' describe?

Accepted Answer

The difficulty of simultaneously achieving decentralization, security, and scalability in a single blockchain

Answer

Coined by Vitalik Buterin, the blockchain trilemma states that optimizing for two of (decentralization, security, scalability) typically comes at the expense of the third.

Question 5

Which cross-chain standard does Polkadot use for message passing between parachains?

Accepted Answer

XCM (Cross-Consensus Message Format)

Answer

XCM is Polkadot's language for expressing intent for cross-chain operations, enabling assets and messages to move between parachains and external networks.

CBE - Certified Blockchain Expert Practice Test

CBE - Certified Blockchain Expert Practice Test

CBE Blockchain Interoperability and Scalability 2