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 'perfect forward secrecy' (PFS) in cryptographic key exchange?
Answer: Each session uses a new key so past sessions remain secure even if a long-term key is compromised
PFS ensures that compromise of a long-term private key does not expose past session keys, protecting historical communications.
Which of the following best describes the Diffie-Hellman key exchange?
Answer: Two parties derive a shared secret over a public channel without transmitting it directly
Diffie-Hellman allows two parties to establish a shared secret over an insecure channel without ever transmitting the secret itself.
What does 'salting' a password hash accomplish?
Answer: It prevents two identical passwords from producing the same hash and defeats precomputed rainbow tables
A salt is random data added to a password before hashing, ensuring identical passwords produce different hashes and defeating rainbow table attacks.
Which attack exploits the reuse of a one-time pad or stream cipher keystream?
Answer: Crib-dragging attack
Crib-dragging exploits keystream reuse in stream ciphers or OTPs by XORing two ciphertexts and guessing known plaintext segments.
In asymmetric cryptography, what is the relationship between key length and security level?
Answer: RSA keys must be much longer than symmetric keys to achieve equivalent security
RSA requires ~3072-bit keys to match the security of 128-bit AES because factoring is easier than brute-forcing a symmetric key of the same length.
What is a 'commitment scheme' in cryptography?
Answer: A protocol where a party commits to a value now but can reveal it later without being able to change it
A commitment scheme lets a party lock in a value (hiding it) while being unable to change it later (binding), with the option to reveal it at a chosen time.
Which property of cryptographic hash functions ensures that even a tiny change in input drastically changes the output?
Answer: Avalanche effect
The avalanche effect means a single-bit change in input causes approximately 50% of the output bits to flip, making outputs appear uncorrelated.