FREE Certified Blockchain Professional (CBCP) Cryptography and Hashing Questions and Answers

Question 1

A blockchain network relies on asymmetric cryptography for securing transactions. Which of the following accurately describes the process of creating a valid digital signature for a new transaction?

Accepted Answer

A hash of the transaction data is generated, and this hash is then encrypted with the sender's private key.

Answer

The transaction data is encrypted using the sender's public key, and the resulting ciphertext is the digital signature.

Answer

The entire block's data, including the transaction, is hashed, and the hash is encrypted with the network's master private key.

Answer

The sender's public key is hashed and then encrypted using a symmetric key shared with the recipient.

Question 2

In a Proof-of-Work (PoW) blockchain like Bitcoin, what is the primary function of a 'nonce'?

Accepted Answer

A variable that miners repeatedly change in the block header to find a hash value below a specific target.

Answer

To encrypt the transaction data within a block for confidentiality.

Answer

It is a counter for the number of transactions sent from a specific address, preventing replay attacks.

Answer

The public key of the miner who successfully solves the cryptographic puzzle.

Question 3

Which cryptographic property of a hash function ensures that it is computationally infeasible to find two different inputs that produce the exact same hash output?

Accepted Answer

Collision Resistance

Answer

Preimage Resistance

Answer

Second Preimage Resistance

Answer

Deterministic Output

Question 4

A financial institution is designing a private blockchain. They need to encrypt large volumes of transactional data for storage within the blocks. While asymmetric cryptography is used for signing transactions, which cryptographic method would be most efficient for encrypting the bulk data itself?

Accepted Answer

Symmetric cryptography using a shared secret key.

Answer

Hashing algorithms like SHA-256.

Answer

Asymmetric cryptography using the public key of all network participants.

Answer

Steganography to hide the data within other block components.

Question 5

If a malicious actor manages to find a second, different transaction that produces the same hash as a victim's original, signed transaction, which specific cryptographic security property has been broken?

Accepted Answer

Second Preimage Resistance

Answer

Collision Resistance

Answer

Preimage Resistance

Answer

Avalanche Effect

Question 6

Which of the following best describes the 'avalanche effect' as it relates to cryptographic hash functions used in blockchain?

Accepted Answer

A small change in the input data (e.g., altering a single character in a transaction) results in a drastically different and unpredictable hash output.

Answer

The computational difficulty of finding a valid nonce increases exponentially over time.

Answer

Multiple transactions are bundled together and hashed, creating a cascade of linked data.

Answer

The process of using the previous block's hash as an input for the current block's hash, creating a chain reaction.

A blockchain network relies on asymmetric cryptography for securing transactions.Which of the following accurately describes the process of creating a valid digital signature for a new transaction?

A blockchain network relies on asymmetric cryptography for securing transactions.
Which of the following accurately describes the process of creating a valid digital signature for a new transaction?