American Express Company
Systems and methods for validating transmissions over communication channels

Abstract:

An authentication system may receive an authentication MAC, an integrity MAC, and data transmitted from a payment application and a payment terminal. A local integrity MAC may be generated using the data as an input to a first cryptographic operation. The system may compare the local integrity MAC to the received integrity MAC to authenticate the received integrity MAC. A local authentication MAC may be generated using a second cryptographic operation and compare the local authentication MAC to the received authentication MAC. The system may authenticate the payment application in response to a successful authentication of at least one of the received authentication MAC or the received integrity MAC.