Vitalik Buterin, Co-founder of Ethereum, presented a blockchain scaling solution called Plasma Cash, and even "more scalable" version of existing solution called plasma. To explain the plasma cash model, buterin gives example that if a user deposits some amount of ether to a crypto exchange or any third party service, a Plasma coin would be created with the same value of ether and a unique id that cannot be merged or split.
Since each plasma coin has an owner, the coins are not fully fungible or interchangeable: no one can take another user's coin without the owner of the coin being alerted. In this case, the coin's owner would prevent the potential fraudulent withdrawal through the "compliant system" by showing their "proof data" for their coin's history
Buterin notes that even if hack occurs on an exchange using plasma cash, users will not lose their money:"Regardless if what happens in the exchange, users can run their money through the plasma exit procedure and get their money out."