Architecture and Platforms 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 Architecture and Platforms flashcards as text
What is 'slashing' in Proof of Stake consensus mechanisms?
Answer: Penalizing validators by destroying a portion of their staked tokens for provably malicious behavior
Slashing is a penalty mechanism that burns a portion (or all) of a validator's staked tokens if they double-sign blocks or attempt to attack the network.
What is a 'private blockchain' and what is its primary use case?
Answer: A fully controlled blockchain where access is restricted to a single organization for internal business processes
A private blockchain is centrally controlled by one organization, used primarily for internal data management, auditability, or process automation where public access is unnecessary.
What is the 'Block Header' in blockchain architecture and what data does it typically contain?
Answer: Metadata including the previous block hash, Merkle root, timestamp, nonce, and difficulty target
A block header contains metadata that links the block to the chain, including the hash of the previous block, the Merkle root of all transactions, timestamp, and consensus-specific fields.
What distinguishes an 'optimistic rollup' from a 'ZK-rollup' as layer-2 scaling solutions?
Answer: Optimistic rollups assume transactions are valid and use fraud proofs if challenged, while ZK-rollups use cryptographic validity proofs upfront
Optimistic rollups post transactions assuming validity, allowing a challenge window for fraud proofs, while ZK-rollups attach a cryptographic validity proof with each batch, enabling faster finality.
In a Directed Acyclic Graph (DAG) based blockchain architecture like IOTA, how are transactions confirmed?
Answer: By each new transaction validating two previous transactions, creating a web-like structure instead of a chain
In DAG architectures like IOTA's Tangle, users must validate two prior transactions when submitting their own, creating a mesh of confirmations rather than a linear chain of blocks.
What is the significance of the 'nonce' field in a Bitcoin block header?
Answer: It is the variable miners increment repeatedly to find a hash below the target difficulty
The nonce is a 32-bit number that miners systematically change to alter the block header hash, seeking one that meets the current difficulty target — the core of Proof of Work mining.
What is 'cross-chain atomic swap' technology?
Answer: A trustless exchange of cryptocurrencies between different blockchains without a centralized intermediary
Atomic swaps use Hashed Timelock Contracts (HTLCs) to ensure that a cross-chain trade either fully completes on both chains or is entirely refunded, eliminating counterparty risk.