Fundamentals and Cryptography 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 Fundamentals and Cryptography flashcards as text
What is the main advantage of a public/permissionless blockchain over a private one?
Answer: Open participation and censorship resistance
Public blockchains allow anyone to participate and resist censorship through decentralization.
In hashing, what is a 'salt' primarily used to prevent?
Answer: Precomputed rainbow table attacks
A salt adds randomness so identical inputs produce different hashes, defeating rainbow tables.
What is a 51% attack?
Answer: Controlling a majority of network hash power to manipulate the chain
A 51% attack occurs when an entity controls the majority of mining power, enabling double-spends and reorgs.
What distinguishes a hash function from an encryption function?
Answer: Hashing is one-way, encryption is reversible with a key
Hashing is a one-way transformation, while encryption can be decrypted with the correct key.
What is the purpose of a seed phrase (mnemonic) in a crypto wallet?
Answer: To deterministically recover all private keys
A seed phrase deterministically generates and can restore a wallet's private keys.
Which best describes a 'double-spend' problem?
Answer: Spending the same digital asset more than once
Double-spending is using the same coins in more than one transaction, which consensus prevents.
What is the typical output length, in bits, of SHA-256?
Answer: 256
SHA-256 produces a 256-bit (32-byte) hash output.