Ransomware scrambles your personal files using a random, one-off encryption key. The key is sent to the crooks and then wiped from memory locally, so they have the only copy. Usually, you have to use a payment system such as Bitcoin, so the transaction is hard to trace. But for the most part, the cybercrooks in the ransomware scene have built up a reputation for dishonest reliability, so that if you do pay, you probably will get your data back.”]