This is a nice question. If someone gets to know your card details anyhow, credit card will be life saver.
Credit card works on your credit worthiness. The card fraud cannot cost you a lot of money. credit cards are also more secure.
In case of debit card, the thief can rain al your money at once . It creates a trouble for bank an takes long time to recover.
So, use credit card for transaction and only use debit card when not in possession of credit card.