PORTLAND, OR -- If you're thinking about buying cryptocurrency the Oregon Better Business Bureau is urging caution. Bitcoin is one type of cryptocurrency.  Essentially, it's digital money. Danielle Kane, with the Better Business Bureau, says before buying cryptocurrency you need to understand how it works. There are no guarantees and values can change dramatically very quickly. You get a public key you use to trade the currency and a private key that protects your money. If you lose...it's gone forever. Kane says cryptocurrency investments can easily fail. While transactions are anonymous, the trades are public and it's one way a scammer can take advantage of your private information if you're not careful.