Electronic transaction security system and method

A method for enhancing the security of a payment card transaction involving a payment card number assigned to a user account by a financial institution, the method comprising the steps of:

• generating a time-limited number comprising a first plurality of digits in the time-limited number associated to the financial institution and a second plurality of digits in the time-limited number set to a first number corresponding to a desired expiration date, wherein the time-limited number is not associated with the user account and wherein the desired expiration date is earlier than an expiration date of the payment card number;
• transmitting the time-limited number and data representative of the user account other than the payment card number to the financial institution;
• locating the user account based on the data;
• and
• validating the time-limited number for the transaction based on the second plurality of digits and the data.

A system for generating a time-limited number for use in a payment card transaction involving a payment card issued to a user by a financial institution, wherein the payment card comprises an original payment card number, the system comprising:

• a processing device;
• and
• a medium accessible by the processing device comprising instructions that when executed by the processing device cause the processing device to perform the steps of:
• setting a first plurality of digits in the time-limited number, wherein the first plurality of digits are predetermined digits associated to the financial institution;
• generating a first number corresponding to a desired expiration date through which the time-limited number is valid for acceptance in the payment card transaction, wherein the desired expiration date is earlier than an expiration date of the payment card;
• setting a second plurality of digits in the time-limited number to the first number;
• and
• outputting the time-limited number.