Blockchain Technology Fundamentals Flashcards

What is 'sharding' as a blockchain scalability solution?

Answer: Partitioning the network so each node only processes a subset of transactions

Sharding divides the blockchain into parallel partitions (shards), each processing its own transactions, dramatically increasing total throughput without every node handling everything.

What is a 'zero-knowledge proof' (ZKP) and how is it used in blockchain?

Answer: A cryptographic method to prove knowledge of data without revealing the data itself

ZKPs let one party prove a statement is true (e.g., 'I know a valid transaction') to another party without disclosing any underlying information, enabling privacy and scaling solutions like zk-rollups.

What does 'on-chain governance' mean in a blockchain protocol?

Answer: Protocol upgrade decisions are made and enforced through votes recorded on the blockchain itself

On-chain governance encodes voting and upgrade mechanisms directly in the protocol, allowing token holders to formally propose and ratify changes without relying on off-chain social consensus.

What is a 'rollup' in the context of Ethereum scaling?

Answer: A Layer 2 technique that executes transactions off-chain and posts compressed proofs to the main chain

Rollups bundle many transactions off-chain, submit compressed data or validity proofs to Ethereum's Layer 1, inheriting its security while dramatically increasing throughput and reducing fees.

What is 'selfish mining' in Proof-of-Work blockchains?

Answer: A strategy where a miner withholds discovered blocks to gain a disproportionate share of rewards

In selfish mining, a pool withholds a newly found block, continues mining secretly, and releases the longer chain later, wasting honest miners' work and earning outsized rewards.

What is the 'blockchain trilemma' as described by Vitalik Buterin?

Answer: The trade-off between achieving decentralization, security, and scalability simultaneously

Buterin's trilemma states that blockchains can typically optimize for only two of three properties — decentralization, security, and scalability — at the expense of the third.

What is an 'oracle problem' in blockchain smart contracts?

Answer: The challenge of securely feeding real-world data into a trustless smart contract

Smart contracts can only access on-chain data; oracles bridge external real-world information (prices, weather, events) to the chain, but introduce a trusted intermediary that can be a single point of failure.