CBSE Blockchain Cryptography Fundamentals 3

Question 1

In a Merkle Patricia Trie (used in Ethereum), what is stored at the root node that makes state verification efficient?

Accepted Answer

A cryptographic hash representing the entire state of the trie

Answer

The root hash of a Merkle Patricia Trie cryptographically commits to the entire state, allowing any state element to be verified with a compact proof path.

Question 2

What is the purpose of the RIPEMD-160 hash in Bitcoin address generation?

Accepted Answer

To shorten the SHA-256 hash of a public key into a 160-bit address

Answer

Bitcoin applies SHA-256 followed by RIPEMD-160 to a public key, producing a 160-bit hash that forms the core of a Bitcoin address, saving space.

Question 3

Which attack model assumes the adversary can request signatures on arbitrary messages but cannot choose the message after seeing the signature?

Accepted Answer

Chosen-message attack

Answer

In a chosen-message attack, the adversary selects messages to be signed before seeing any signatures, testing if forging new signatures is possible.

Question 4

A zero-knowledge proof allows a prover to convince a verifier of a statement's truth without revealing:

Accepted Answer

Any information beyond the validity of the statement itself

Answer

Zero-knowledge proofs allow the prover to demonstrate knowledge of a secret (e.g., a private key) without disclosing any information about the secret itself.

Question 5

In HD (Hierarchical Deterministic) wallets defined by BIP-32, child private keys are derived using HMAC-SHA512 applied to:

Accepted Answer

The parent public key (or private key) and a chain code

Answer

BIP-32 child key derivation uses HMAC-SHA512 with the parent key material and chain code as inputs, producing a deterministic child key and new chain code.

(CBSE) Certified Blockchain Security Expert Practice Test

(CBSE) Certified Blockchain Security Expert Practice Test

CBSE Blockchain Cryptography Fundamentals 3