CSC is only one of many options to improve checkout conversion. There are many other ones that don't result in increased fraud exposure like:

- Eliminate the concept of a shopping cart if you just sell one product

- Don't force buyers to create an account

- Don't ask for the same information twice like shipping and billing address (if you collect billing address, you shouldn't)

- Combine first and last name into one field: name

- Auto-complete address based on ZIP

- Trust messaging

Baymard has great recommendations based on their extensive studies: http://baymard.com/checkout-usability