A DeFi lending platform needs to obtain real-time price data for collateral assets to trigger liquidations. The team is choosing between a single centralized oracle and a decentralized oracle network. What is the primary trade-off they must consider?

Centralized oracles are cheaper and faster, but they introduce a single point of failure; decentralized oracles are more secure but can be slower and more expensive.

Centralized oracles are more accurate, while decentralized oracles are less accurate.

Centralized oracles cannot be used for financial applications.

Decentralized oracles are always cheaper than centralized oracles.

A team has written a smart contract for a decentralized exchange. Before deploying to mainnet, they want to validate that the contract behaves correctly under various market conditions. Which testing strategy is most comprehensive?

Use a combination of unit tests, integration tests on a testnet, and formal verification.

Perform a manual code review by the development team only.

Run unit tests on a local development network with mocked token prices.

Deploy to a public testnet and run integration tests with real test tokens.

A team is designing a smart contract for a loyalty program where users earn points for purchases. The contract must store each user's points balance and transaction history. The team wants to minimize gas costs for frequent point updates. Which approach is most gas-efficient?

Store the full transaction history in an array of structs within the contract.

Store only the current points balance in a mapping, and emit an event for each transaction instead of storing the full history on-chain.

Store the points balance and history in a single string variable encoded as JSON.

Use a mapping of user address to an array of transaction structs.

Which practice is a recommended security measure to protect against integer overflow/underflow in Solidity?

Using Solidity 0.8.x or later, which includes built-in overflow checks

Using floating-point numbers for balances

Using unchecked blocks for all arithmetic

EC-CouncilBlockchain Business Leader Certification

Domain 4Objective 3

Smart Contract Requirements and Architecture BBLC Practice Questions (Page 8)

Part of the Ethereum, Smart Contracts, and dApps domain, which makes up ~14% of our current practice bank.

41questions here

9free pages

9concepts

Questions 36–40

36expert · hard
A DeFi lending platform needs to obtain real-time price data for collateral assets to trigger liquidations. The team is choosing between a single centralized oracle and a decentralized oracle network. What is the primary trade-off they must consider?
Select an answer first
37foundation · easy
Which testing framework is specifically designed for writing and running automated tests for Ethereum smart contracts?
Select an answer first
38application · medium
A team has written a smart contract for a decentralized exchange. Before deploying to mainnet, they want to validate that the contract behaves correctly under various market conditions. Which testing strategy is most comprehensive?
Select an answer first
39expert · hard
A team is designing a smart contract for a loyalty program where users earn points for purchases. The contract must store each user's points balance and transaction history. The team wants to minimize gas costs for frequent point updates. Which approach is most gas-efficient?
Select an answer first
40foundation · easy
Which practice is a recommended security measure to protect against integer overflow/underflow in Solidity?
Select an answer first

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