It is worth mentioning here that way you had earlier swiped the debit card at point of sale (POS) machines is going to change as wef 01 Dec 2013; you will get a prompt for entering the PIN at Point of Sale terminals for Debit Card transactions. Have a look at the below screenshot which also shows that this feature may or may not occur in international transactions.
This is an effort by the RBI to
prevent online frauds or fraudulent transactions on the point of sale machines.