Certified Blockchain Professional (CBCP) MCQ Flashcards

What is the key difference between a 'custodial' and 'non-custodial' cryptocurrency wallet?

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.

In Hyperledger Fabric's endorsement policy, what determines which peers must sign a transaction before it is considered valid?

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.

Which cryptographic algorithm does Bitcoin use for generating public-private key pairs?

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.

What is the primary purpose of a 'multi-signature' (multisig) wallet configuration such as 2-of-3?

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.

In the context of Decentralized Autonomous Organizations (DAOs), what is a 'governance attack'?

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.

What role does the 'genesis block' play in a blockchain network?

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.

When evaluating a blockchain solution for a use case, which scenario is LEAST suitable for blockchain implementation?

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.