Cryptography in Blockchain Flashcards
7 cards from real Blockchain Technology 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 in Blockchain flashcards as text
What is a commitment scheme in cryptography, and how is it used in blockchain protocols?
Answer: A method to bind a value secretly, then reveal it later without being able to change it
A commitment scheme allows a party to commit to a value (hiding it) and later open (reveal) it, with the guarantee it cannot be altered after committing.
Which attack does the 'avalanche effect' in hash functions help defend against?
Answer: Differential cryptanalysis and pattern detection
The avalanche effect ensures a single-bit change in input causes roughly half the output bits to flip, making differential analysis impractical.
In SNARKs (Succinct Non-interactive Arguments of Knowledge), what is the 'trusted setup' and why is it controversial?
Answer: A one-time parameter generation where secret 'toxic waste' must be destroyed to ensure soundness
The trusted setup generates public parameters; if the secret randomness ('toxic waste') is not destroyed, it could allow forging false proofs.
Which of the following describes a 'birthday attack' against a hash function?
Answer: Finding two arbitrary inputs that collide by exploiting the birthday paradox's probability threshold
The birthday paradox shows that collisions become likely after approximately √(2^n) attempts for an n-bit hash, far fewer than brute-forcing a specific pre-image.
What is a Pedersen commitment and how does it differ from a simple hash commitment?
Answer: A Pedersen commitment is homomorphic, allowing mathematical operations on committed values without revealing them
Pedersen commitments are additively homomorphic, meaning commitments to values can be added together in a way that corresponds to adding the underlying values.
In the context of ring signatures (used in Monero), what anonymity property do they provide?
Answer: They allow a signer to sign on behalf of a group, making it impossible to identify which member signed
A ring signature proves that one member of a defined group signed the message, but reveals nothing about which specific member did so.
What is the difference between a 'hot wallet' and a 'cold wallet' from a cryptographic key management perspective?
Answer: Hot wallets keep private keys on internet-connected devices; cold wallets store keys offline to reduce exposure
The critical distinction is network exposure: hot wallet private keys are accessible online (higher risk), while cold wallet keys are kept offline (air-gapped).