FREE Blockchain Developer Blockchain Fundamentals and Cryptography Questions and Answers Flashcards
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Read the first 6 FREE Blockchain Developer Blockchain Fundamentals and Cryptography Questions and Answers flashcards as text
What is the difference between a public key and a blockchain address?
Answer: An address is typically a hashed and encoded version of the public key
A blockchain address is usually created by hashing the public key with SHA-256 and RIPEMD-160, then encoding it with Base58Check for a shorter, error-resistant format.
What does the term 'finality' mean in blockchain consensus?
Answer: The guarantee that a confirmed transaction cannot be reversed or altered
Finality refers to the assurance that once a transaction is included in a block and sufficiently confirmed, it is permanent and irreversible.
How does a digital signature prove both authenticity and integrity of a blockchain transaction?
Answer: By hashing the transaction data and encrypting the hash with the sender's private key
The sender signs a hash of the transaction with their private key, and anyone can verify it using the sender's public key, confirming both who sent it and that the data was not altered.
What problem does the Byzantine Fault Tolerance (BFT) concept address in distributed systems?
Answer: Reaching consensus when some participants may be unreliable or malicious
BFT addresses how a distributed network can reach agreement on a single value even when some nodes fail or act maliciously.
What is the role of SHA-256 in the Bitcoin mining process?
Answer: It is the hash function miners must compute repeatedly to find a valid block hash below the target
Bitcoin mining requires repeatedly computing SHA-256 on the block header with different nonces until the resulting hash is below the current difficulty target.
What is a hash collision and why is it significant for blockchain security?
Answer: When two different inputs produce the same hash output, potentially allowing data forgery
A hash collision occurs when two distinct inputs yield an identical hash, which could undermine blockchain integrity if an attacker could produce collisions on demand.