To minimize the potential damage of an attacker gaining access to your credit card information, consider opening a credit card account for use only online. Keep a minimum credit line on the account to limit the amount of charges an attacker can accumulate.
In addition, some companies offer a phone number you can use to provide your credit card information. Although this does not guarantee that the information will not be compromised, it eliminates the possibility that attackers will be able to hijack it during the submission process.