Practice Test Geeks(CBSE) Certified Blockchain Security Expert Practice Test
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Blockchain Cryptography Fundamentals Flashcards

7 cards from real CBSE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Blockchain Cryptography Fundamentals flashcards as text

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

    Answer: A cryptographic hash representing the entire state of the trie

    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.

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

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

    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.

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

    Answer: Chosen-message attack

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

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

    Answer: Any information beyond the validity of the statement itself

    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.

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

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

    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.

  6. Which of the following describes a length extension attack and which hash construction is vulnerable to it?

    Answer: Forging a valid hash by appending data; SHA-2 Merkle-Damgård constructions are vulnerable

    Length extension attacks exploit Merkle-Damgård construction internals (used by SHA-256) to compute H(key||message||extension) without knowing the key.

  7. What does the 'binding' property of a cryptographic commitment scheme guarantee?

    Answer: The committer cannot change the committed value after publishing the commitment

    Binding ensures that once a commitment is published, the committer is bound to a specific value and cannot later open the commitment to a different value.