Core Cryptographic Principles Flashcards
7 cards from real Cryptocurrency practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Core Cryptographic Principles flashcards as text
What is a zero-knowledge proof (ZKP) used for in cryptocurrency?
Answer: Proving a transaction is valid without revealing any underlying private data
ZKPs allow one party to prove knowledge of a secret (e.g., a valid transaction) to another party without revealing the secret itself.
What is the significance of using a cryptographically secure pseudo-random number generator (CSPRNG) in wallets?
Answer: It ensures private keys are generated with sufficient entropy and cannot be predicted
A CSPRNG provides unpredictable, high-entropy randomness essential for generating private keys that cannot be guessed or reproduced by attackers.
In HMAC (Hash-based Message Authentication Code), what role does the key play?
Answer: It is mixed with the message before hashing to bind authentication to a specific secret
HMAC XORs the key with padding constants and uses it in two nested hash operations, ensuring only parties with the secret key can verify or produce the MAC.
Which of the following correctly describes the difference between confusion and diffusion in block ciphers?
Answer: Confusion obscures the relationship between key and ciphertext; diffusion spreads plaintext influence across the ciphertext
Shannon defined confusion (obscuring key-ciphertext relationships, via substitution) and diffusion (spreading plaintext influence, via permutation) as the two core principles of secure ciphers.
What is Shamir's Secret Sharing used for in cryptocurrency key management?
Answer: Splitting a private key into multiple shares so a threshold number can reconstruct it
Shamir's Secret Sharing splits a secret into N shares where any K shares can reconstruct the secret, enabling threshold-based key custody without a single point of failure.
What does it mean for an encryption scheme to be 'semantically secure'?
Answer: An attacker cannot learn any partial information about the plaintext from the ciphertext
Semantic security (IND-CPA) means a computationally bounded attacker gains no information about the plaintext by observing the ciphertext.
Why is ECB (Electronic Codebook) mode considered insecure for encrypting structured data?
Answer: Identical plaintext blocks always produce identical ciphertext blocks, revealing data patterns
ECB encrypts each block independently, so repeated plaintext blocks produce repeated ciphertext blocks, leaking structural information (famously illustrated by the 'ECB penguin').