Cryptocurrency is basically a digital form of currency which runs on power full blockchain technology. Each type of these cryptocurrencies are different and have their own way of working. The technology which governs these are same and that’s Blockchain.
If you take example of Ethereum, It talks about smart contracts. So imagine that you an impoter and you got into a contract with an exporter located in some other country. Going by the present rule, you will have to involve a bank in both the countries to complete the transaction of money and documents.
Now if you take the route of doing it by creating a smart contract with Ethereum to carry out and verify your trade transaction without involving any central banks or any other financial institution to that matter.
We cannot hack these kind of block chains because we should hack every block to access another block so it is best method for investing money.