Blockchain Exam Questions and
Answers 100% PASS
Why is securing a digital asset difficult? - CORRECT ANSWER--Can be
duplicated without loss of quality
-Ownership can be manipulated
-Double spending
-We use trusted intermediaries
Single central ledger vs distributed ledger - CORRECT ANSWER-Single: Trusted
record keeper. Holder of assets is sole arbiter of payment.
- Can: refuse certain transactions, manipulate balances, charge fees, act slowly --
single point of failure
Distributed: Every node has copy of ledger. Unsynchronized. No single point of
failure. Each node may have different view of system. Requires CONSENSUS to
accept transactions.
, Permissioned vs. permissionless ledger - CORRECT ANSWER-Permissioned
(private) blockchains: Only approved members can be nodes. Validating blocks do
not require an arbitrary puzzle. Blocks Can be assigned systematically. Decisions
enforced by committee.
Most financial services applications will be permissioned + trusted.
Permissionless(public/bitcoin): Anyone can be a miner and validate transactions.
Need significant inestment in tech (processors, power, cooling). Consensus by
proof of work, requires incentives. Decisions must be made by consensus of
miners.
What is a double spend attack? - CORRECT ANSWER-Since digital assets can be
perfectly replicated with no effort, demonstrated ownership is not enough. Double
spend occurs when someone tries to use the same money twice. Right now, only
defense is single trusted authority.
How is P2P file sharing different from normal client server? - CORRECT
ANSWER-Client server: Your web browser sends a request to a server via internet
for a specific piece of info. Sent back in packets. Has single point of failure(DDOS
attacks). Popular servers can be overwhelmed.
© 2026 Copyright. All Rights Reserved. This document is
protected by copyright law
Answers 100% PASS
Why is securing a digital asset difficult? - CORRECT ANSWER--Can be
duplicated without loss of quality
-Ownership can be manipulated
-Double spending
-We use trusted intermediaries
Single central ledger vs distributed ledger - CORRECT ANSWER-Single: Trusted
record keeper. Holder of assets is sole arbiter of payment.
- Can: refuse certain transactions, manipulate balances, charge fees, act slowly --
single point of failure
Distributed: Every node has copy of ledger. Unsynchronized. No single point of
failure. Each node may have different view of system. Requires CONSENSUS to
accept transactions.
, Permissioned vs. permissionless ledger - CORRECT ANSWER-Permissioned
(private) blockchains: Only approved members can be nodes. Validating blocks do
not require an arbitrary puzzle. Blocks Can be assigned systematically. Decisions
enforced by committee.
Most financial services applications will be permissioned + trusted.
Permissionless(public/bitcoin): Anyone can be a miner and validate transactions.
Need significant inestment in tech (processors, power, cooling). Consensus by
proof of work, requires incentives. Decisions must be made by consensus of
miners.
What is a double spend attack? - CORRECT ANSWER-Since digital assets can be
perfectly replicated with no effort, demonstrated ownership is not enough. Double
spend occurs when someone tries to use the same money twice. Right now, only
defense is single trusted authority.
How is P2P file sharing different from normal client server? - CORRECT
ANSWER-Client server: Your web browser sends a request to a server via internet
for a specific piece of info. Sent back in packets. Has single point of failure(DDOS
attacks). Popular servers can be overwhelmed.
© 2026 Copyright. All Rights Reserved. This document is
protected by copyright law
