Patent attributes
Authentication includes receiving an indication of physical possession of a payment card by a merchant and receiving a purchase request for an authorization of an exchange from the payment account of the cardholder to the merchant. Authentication includes assigning a randomized transaction identifier to the request for the authorization of the exchange. The method also includes transmitting the request for the authorization of the exchange from the payment account of the cardholder to the merchant and receiving the assigned randomized transaction identifier and a randomized authentication identifier associated with the randomized transaction identifier from a payment association, the payment association determining whether the request for the authorization of the exchange is valid. Authentication includes transmitting a copy of the randomized authentication identifier to the mobile device and receiving validation that the transmitted copy of the randomized authentication identifier from the mobile device matches the randomized authentication identifier.