Abstract: The public Internet is the world's largest system of inter-networked computers. Adequate security means for protecting sensitive data communicated over the Internet is not, however, provided. The present invention, therefore, provides a system and method for performing secure transactions over an insecure packet-switched communication network. This is achieved by interconnecting a number of master nodes over the insecure communication network. The master nodes are capable of transmitting encrypted data packets over the insecure network via pseudo-random communication paths. The master nodes are further capable of returning to any state in a secure transaction in the event of a network failure. The master nodes are also capable of using new keys to encrypt each data packet.

Abstract: A terminal adapter, along with a value added network, is disclosed that interworks a plurality of terminals with a processing host to accomplish transaction processing. The terminals can use different protocols and typically incorporate card readers for completing financial or other types of transactions typically involving credit, debit, ATM or similar cards. The terminal adapter provides reliable and secure communication using a network based in part on the Internet as a primary form of communication. The terminal adapter also provides a secondary communication path in the event of a failure of the primary communication path, as well as automatic recognition of different terminal protocols, various security functions, error detection, and other network administration functions to ensure a flexible system and efficient transaction processing system.