An improved method and system for conducting secure payments over a computer network

摘要

A method of conducting a transaction involving a merchant over an electronic payment network, includes receiving data related to the transaction from the merchant, and computing a message authentication code based on the data related to the transaction. The message authentication code 5 and the data related to the transaction are placed in a portion of the discretionary data field of a standard payment card magnetic stripe track format compatible with ISO 7813 to form a track image. The track image including a message authentication code is transmitted to an acquirer for processing as a point-of-sale transaction, before or without first storing the message authentication code on a magnetic stripe of a payment card.