If you own any cryptocurrency, you’ll need to adapt to a new way of keeping your money safe. You can’t just keep your Bitcoins under the bed or deposit your Ether in a bank (at least, not yet). So what are you supposed to do? Here are 10 common security mistakes people make when handling and storing cryptocurrency. Mistake 1: Failing to Back Up Wallet Keys Cryptocurrencies don’t come with online banking and password resets.