There are 3 levels of security while making online transaction. When doing online transaction, you first need to enter the card details. This includes not only the card number but also other info like expiry date and cvv code. This is supposed to be the first level of security as to do so one needs to have the card with him. However, a fraudster can easily note these details, even if they get your card for a short time eg when you give your card to the waiter to pay your dinner bill, you don’t know if he is noting down your details or taking a snap on this mobile phone.
The next level of security is the OTP that the bank sends to the valid customer. This is probably the most useful security tool as customers normally keeps the mobile with them at all times. The third level of security is the transaction alert, which is same as already discussed above.
Credit card frauds became wide-spread a few years back, when the banks went on overdrive to provide credit cards to just about anybody with an income. It included many who were not too familiar with financial transactions and were the prime targets of fraudsters.
The banks have a tricky job to balance the security aspect without making usage of credit card too inconvenient to the customer. It thus puts a lot of responsibility of the safe-keeping on the customer himself.