C|BP
Free EC-Council Certified Blockchain Professional Practice Test
12 exam-style questions with full explanations — no sign-up. Score yourself, then close your gaps with the full course.
Exam fee ~$5995 exam domainsLevel Intermediate to Advanced2 timed practice tests in the course
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A group of five banks wants to build a shared ledger for interbank settlements where only known, vetted participants can join, transaction details must remain private between counterparties on a need-to-know basis, and no cryptocurrency mining is required. Which platform BEST meets these requirements?
Corda was purpose-built for regulated financial institutions: it uses a permissioned network of identified participants, shares transaction data only with the parties involved in a deal (need-to-know privacy via notary-based validation rather than global broadcast), and does not require a native mining-based consensus token.
A company wants to issue digital trading cards where each card is unique, non-fungible, and individually identifiable on the Ethereum network. Which token standard should they implement?
ERC-721 is the standard for non-fungible tokens (NFTs), where each token has a unique tokenId and distinct metadata, making it suitable for unique collectibles like trading cards.
A developer is initializing a new private Ethereum network for internal testing and creates a genesis.json file. Which field in this file must be set to a unique value to prevent the private network from accidentally connecting to the public Ethereum mainnet or other test networks?
chainId (along with networkId) uniquely identifies the network and is used by nodes to reject peers and transactions from a different network, preventing accidental cross-network connections.
A security auditor reviews a Solidity withdraw function that sends ETH to the caller using a low-level call, then afterward sets the caller's internal balance to zero. The auditor flags this as a critical vulnerability. Which fix correctly addresses the root cause?
This is the classic reentrancy vulnerability pattern (as seen in the DAO hack). Updating state (effects) before performing the external call (interaction) prevents an attacker's fallback function from re-entering the withdraw call and draining funds repeatedly before the balance is zeroed.
A mid-size retailer wants a system where its 50 internal departments can share inventory counts in real time. Only the retailer controls the servers, all departments already trust each other under one corporate IT policy, and updates need sub-second latency with a single writer at a time. Which approach is BEST?
When all participants are under one trust domain, there is no need for distributed consensus, immutability guarantees, or decentralization — a centralized database delivers the required latency and simplicity with far less overhead. This is the classic 'do you even need blockchain' exam scenario.
A blockchain network needs to reduce energy consumption compared to Bitcoin's mining-based consensus while still achieving Sybil resistance through economic stake rather than computational work. Which consensus mechanism should be selected?
Proof of Stake secures the network by requiring validators to lock up (stake) economic value; validator selection is proportional to stake rather than computational effort, drastically cutting energy use while still deterring Sybil attacks through financial risk.
Which Ethereum account type has no associated private key and instead is controlled entirely by its deployed code, executing logic only when triggered by a transaction or message call?
Contract accounts store bytecode that runs on the EVM whenever the account receives a transaction or message call, and they are controlled by code logic rather than a private key.
A team is standing up a private Ethereum PoW network for a lab exercise and wants blocks to mine within a few seconds instead of minutes, since there are only two low-power nodes. Which genesis.json setting should they adjust?
Setting a low difficulty value in the genesis file makes the proof-of-work puzzle trivial to solve on low-power hardware, allowing rapid block production suitable for private/test networks.
A payments platform needs to support thousands of instant, low-fee micro-transactions exchanged repeatedly between the same two known parties, with only the opening and closing balances ultimately settled on the base chain. Which scaling approach BEST fits this use case?
State channels let two (or more) known counterparties exchange an unlimited number of off-chain signed transactions instantly and with no per-transaction fee, then submit only the final settlement to the main chain — exactly matching the fixed-counterparty, high-frequency scenario described.
Five competing pharmaceutical distributors want to jointly track drug shipments to prove provenance and prevent counterfeiting. No single distributor is willing to let another host or control the shared ledger, but all five agree on a fixed governance charter and validator list. Which blockchain design fits this requirement?
Multiple independent, mutually distrusting organizations that need shared control and a jointly agreed validator set is the defining scenario for a consortium/permissioned blockchain — no single party controls it, but access and validation are restricted to known members.
In the Bitcoin protocol, mining difficulty is automatically recalculated after how many blocks to keep the average block interval near 10 minutes?
Bitcoin recalculates the mining difficulty every 2016 blocks (roughly every two weeks, given a 10-minute target block time), comparing the actual time taken against the expected time to adjust the target hash threshold.
During a DApp transaction, the actual computation consumes more gas than the gas limit specified by the sender. What is the outcome?
When execution runs out of gas before completing, the EVM reverts all state changes (an 'out of gas' exception), but the gas already consumed computing up to that point is still paid to miners/validators and is not refunded.
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How much does the C|BP exam cost?
The exam fee is approximately $599 and varies by region — confirm current pricing with the certification vendor before you book.
What topics are on the exam?
It covers 5 domains: Blockchain Fundamentals (20% (author estimate)), Ethereum, DApps, and the Blockchain Ecosystem (20% (author estimate)), Smart Contracts and Blockchain Implementation (30% (author estimate)), Advanced Blockchain: Scalability, Security, and BaaS (22% (author estimate)), Applied Blockchain Judgment and Use-Case Selection (8% (author estimate)). The full course has a dedicated chapter, lab and practice-test coverage for each.
Is this practice test really free?
Yes — all questions on this page are free with explanations and no sign-up. The paid Udemy course adds two full-length timed exams, video lessons and hands-on labs.
Will this prepare me for the real exam?
The questions mirror the real exam's style and are mapped to the official domains. This is exam-focused preparation — combine the free test with the full course's timed simulations to gauge your readiness.