01When you pay on the Internet, you fill in your card details.
02We send you a one-time password in sms.
03You enter the password on a separate secure page to complete the purchase.
For reasons of safety the seller's website should support Mastercard SecureCode or Verified by Visa technology.
If it does not support, then you will pay for the purchase without a one-time password. On such sites, under the rules of Visa and Mastercard, the seller will be liable for fraud with your card.