Blockchain Fundamentals Flashcards

What is the primary purpose of a Merkle tree in blockchain architecture?

Answer: To efficiently verify the integrity of large datasets

Merkle trees allow any transaction in a block to be verified by checking only a logarithmic number of hashes rather than the entire dataset.

Which characteristic best describes a 'permissioned' blockchain?

Answer: Participation requires authorization from a governing entity

Permissioned blockchains restrict who can join and transact, making them common in enterprise and consortium settings.

In blockchain terminology, what is a 'genesis block'?

Answer: The very first block in a blockchain

The genesis block (block 0) is hard-coded as the starting point of a blockchain with no predecessor hash.

What does 'block finality' mean in the context of blockchain?

Answer: A confirmed block can never be reversed or altered

Finality guarantees that once a block is confirmed, its transactions are irreversible and permanently part of the ledger.

How does a hard fork differ from a soft fork?

Answer: A hard fork creates a permanent chain split; a soft fork remains backward-compatible

A hard fork introduces protocol changes that non-upgraded nodes cannot follow, potentially creating two separate chains, while a soft fork is backward-compatible.

What role does a 'full node' play in a blockchain network?

Answer: It stores a complete copy of the blockchain and independently validates all rules

Full nodes store the entire blockchain history and enforce all consensus rules, providing maximum trustlessness and security.

What is the significance of the 'nonce' field in a blockchain block header?

Answer: It is a number miners adjust to find a valid proof-of-work hash

Miners iterate the nonce value until the block hash falls below the network's current difficulty target, proving computational work.