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Cryptography Flashcards

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

Read the first 7 Cryptography flashcards as text
  1. What is the BIP-39 standard primarily used for in cryptocurrency wallets?

    Answer: Encoding a wallet seed as a human-readable mnemonic phrase

    BIP-39 defines how to encode 128-256 bits of entropy as a 12-24 word mnemonic phrase from a fixed wordlist, making wallet backup human-friendly.

  2. What is the key difference between ZK-SNARKs and ZK-STARKs?

    Answer: STARKs do not require a trusted setup ceremony and are quantum-resistant

    ZK-STARKs rely only on hash functions (making them quantum-resistant) and require no trusted setup, unlike ZK-SNARKs which need a trusted ceremony and use elliptic curve pairings.

  3. In the context of public-key cryptography, what does 'key encapsulation' accomplish?

    Answer: It wraps a symmetric key inside an asymmetric encryption operation for secure transmission

    Key encapsulation mechanisms (KEMs) use asymmetric cryptography to securely transmit a symmetric session key, which then encrypts the actual data more efficiently.

  4. Which attack exploits the birthday paradox to find hash collisions more efficiently than brute force?

    Answer: Birthday attack

    A birthday attack exploits the birthday paradox: finding any two inputs with the same hash requires only approximately √(2^n) operations rather than 2^n, halving the effective security bits.

  5. What property does a cryptographic accumulator provide that a Merkle tree also provides?

    Answer: Compact membership proofs for elements in a set

    Both cryptographic accumulators and Merkle trees enable compact proofs of membership (and sometimes non-membership) for elements in a large set.

  6. What is the main cryptographic purpose of HMAC compared to a plain hash?

    Answer: HMAC authenticates both message integrity and the identity of the sender by incorporating a secret key

    HMAC (Hash-based Message Authentication Code) combines a secret key with the message hash, so only parties holding the key can verify or produce a valid MAC.

  7. Why is the discrete logarithm problem central to the security of elliptic curve cryptography (ECC)?

    Answer: Given a public key (point on the curve), it is computationally infeasible to find the private key (scalar)

    ECC security relies on the elliptic curve discrete logarithm problem (ECDLP): given points P and Q=kP, finding the scalar k is computationally infeasible on properly chosen curves.