CBCP Certified Blockchain Professional (CBCP) MCQ 5 — Questions and Answers
Question 1: What is the key difference between a 'custodial' and 'non-custodial' cryptocurrency wallet?
- Custodial wallets use hardware security modules; non-custodial use software only
- Custodial wallets hold private keys on behalf of users; non-custodial wallets give users full key control (Correct answer)
- Custodial wallets support only Bitcoin; non-custodial wallets support multiple chains
- Custodial wallets charge higher fees; non-custodial wallets are always free
Correct answer: Custodial wallets hold private keys on behalf of users; non-custodial wallets give users full key control
In custodial wallets (e.g., exchange wallets), a third party controls private keys; non-custodial wallets ensure users retain sole control of their keys and therefore their funds.
Question 2: In Hyperledger Fabric's endorsement policy, what determines which peers must sign a transaction before it is considered valid?
- The peer with the highest computational power automatically endorses all transactions
- The chaincode-specific endorsement policy defining required organizational signatures (Correct answer)
- The orderer node selects endorsers based on current network load
- All peers in the channel must endorse every transaction by default
Correct answer: The chaincode-specific endorsement policy defining required organizational signatures
Hyperledger Fabric endorsement policies are defined per chaincode and specify which organizations' peers must simulate and sign a transaction proposal for it to be valid.
Question 3: Which cryptographic algorithm does Bitcoin use for generating public-private key pairs?
- RSA-2048
- Ed25519 (Edwards-curve DSA)
- Elliptic Curve Digital Signature Algorithm (ECDSA) on secp256k1 (Correct answer)
- AES-256 with Diffie-Hellman key exchange
Correct answer: Elliptic Curve Digital Signature Algorithm (ECDSA) on secp256k1
Bitcoin uses ECDSA on the secp256k1 elliptic curve to generate key pairs, enabling compact signatures and efficient verification suitable for a distributed network.
Question 4: What is the primary purpose of a 'multi-signature' (multisig) wallet configuration such as 2-of-3?
- It increases transaction throughput by parallelizing signature verification
- It requires M of N keyholders to authorize a transaction, reducing single-point-of-failure risk (Correct answer)
- It encrypts wallet data with multiple layers of AES encryption keys
- It enables gasless transactions by distributing fee payment across signers
Correct answer: It requires M of N keyholders to authorize a transaction, reducing single-point-of-failure risk
A 2-of-3 multisig wallet requires any 2 of 3 designated private keys to sign a transaction, providing security redundancy — loss of one key doesn't lock funds, and theft of one key isn't sufficient to steal funds.
Question 5: In the context of Decentralized Autonomous Organizations (DAOs), what is a 'governance attack'?
- A DDoS attack targeting DAO's front-end voting interface
- An entity accumulates enough governance tokens to pass malicious proposals (Correct answer)
- A 51% mining attack that rewrites the DAO's deployment transaction
- Smart contract bugs that prevent token holders from casting votes
Correct answer: An entity accumulates enough governance tokens to pass malicious proposals
A governance attack occurs when an adversary acquires a controlling share of governance tokens — sometimes via flash loans — to push through self-serving or malicious proposals before others can react.
Question 6: What role does the 'genesis block' play in a blockchain network?
- It contains the smart contract bytecode for the core consensus protocol
- It is the first block hardcoded into the software, establishing the chain's starting state (Correct answer)
- It is regenerated monthly to reset chain difficulty to baseline
- It stores validator private keys encrypted with the network's master seed
Correct answer: It is the first block hardcoded into the software, establishing the chain's starting state
The genesis block (block 0) is the first block in a blockchain, hardcoded into the node software, and establishes the initial state from which all subsequent blocks are linked.
Question 7: When evaluating a blockchain solution for a use case, which scenario is LEAST suitable for blockchain implementation?
- Cross-border remittances requiring trust between multiple banks
- A single company's internal inventory database with one trusted administrator (Correct answer)
- Supply chain provenance tracking across competing manufacturers
- Decentralized peer-to-peer lending without a central credit authority
Correct answer: A single company's internal inventory database with one trusted administrator
A single organization with one trusted administrator gains no benefit from blockchain's decentralized trust model; a traditional centralized database is simpler, faster, and cheaper for this use case.
CBCP Certified Blockchain Professional (CBCP) MCQ 5
What is the key difference between a 'custodial' and 'non-custodial' cryptocurrency wallet?