System and method for performing secure electronic transactions over an open communication network

Claim 1

A system for performing an electronic transaction over an open communication network (20) between a customer (10) and a merchant (30) which is connected to said open network, the customer having a cellular telephone (50) with an identification chip-card (SIM) working on a GSM network, said system comprising: a computer terminal (10) connected to said open network (20), an acquirer center (40) having an acquirer gateway (41) linked to said open network (20) for permitting secured communication using an encryption protocol between said terminal (10) and said acquirer center (40) and between said merchant (30) and said acquirer center (40) through said open network (20) to initiate the transaction, characterized in that said acquirer center (40) further comprises means associated with said acquirer gateway (41) for generating a PIN-Code specific to said transaction responsive to a request from the customer to complete the transaction, an identification server (42) associated with said acquirer gateway (41) for transmitting said transaction-specific PIN code as a message to the customer's cellular telephone (50) over the GSM network to permit said customer to enter a response code in said terminal (10), said response code being based on said transmitted message, comparing means associated with said acquirer gateway (41) for comparing said response code entered on said terminal (10) to an expected response code, and authorization means (43) for authorizing said transaction only when the response code entered on said terminal (10) matches the expected response code based on said transmitted message.

Claim 6

A method for performing an electronic transaction over an open communication network (20) between a customer and a merchant (30) which is connected to said open network, the customer having a cellular telephone (50) with an identification chip-card (SIM) working on a GSM network, said method comprising the steps of: establishing communication between a computer terminal (10) and said merchant (30) offering a transaction over said open communication network (20), and establishing communication between said terminal (10) and an acquirer center (40) responsive to a request from said customer to initiate the transaction, said acquirer center (40) being operatively linked to said terminal (40) and said merchant (30) over said open communication network (20) through an acquirer gateway (41), the communication employing an encrypted protocol, characterized in comprising the steps of: generating a PIN-code specific to said transaction generated from said acquirer gateway (41) and transmitting said transaction-specific PIN code to said customer's cellular telephone (50) as a message over the GSM network responsive to a request from the customer to complete the transaction, entering, in said terminal (10), a response code based on said transmitted message, said response code being transmitted to said acquirer gateway (41) over said open communication network (20), comparing, by the acquirer center (40), said response code with an expected response code, and confirming validity of the transaction only when the response code entered on said terminal (10) matches the expected response code based on said transmitted message to authorize the transaction.