A global digital art marketplace allows artists to sell digital artwork using a decentralised cryptocurrency operating on a public blockchain ledger.
Compare centralised digital currency with decentralised cryptocurrency by giving two key differences.
The diagram illustrates three consecutive blocks in the marketplace's blockchain ledger: Block #88, Block #89, and Block #90. An attacker attempts to modify a transaction recorded in Block #89 from '2.5 Coins' to '250 Coins'. Explain how the structure of the blockchain prevents this fraudulent alteration from being accepted by the network.
Explain what is meant by the 'double-spending problem' in digital currency systems and describe how blockchain consensus prevents it.
State one benefit and one drawback to an artist of using cryptocurrency rather than traditional bank transfers for international artwork sales.