Patent ID: 7668782

Claim:
An electronic commerce system comprising: a client computer; and a server computer; the client computer and the server computer being interconnected by a public packet switched communications network; the client computer being programmed to transmit to the server computer an order acceptance request comprising a plurality of terms or conditions of a proposed offer for a purchase, the order acceptance request comprising a discrete message that includes a plurality of modular elements whose individual integrity is protected by embedding cryptographic security codes within each of the modular elements, at least one of the modular elements individually protected by a cryptographic security code being a digital coupon; the server computer being programmed to process the order acceptance request based on pre-programmed criteria, including authentication of the cryptographic security codes embedded within each of the modular elements and examination of the modular elements of the discrete message individually protected by the cryptographic security codes, and, based on the processing of the order acceptance request, to transmit to the client computer an order acceptance response based on the pre-programmed criteria, the order acceptance response comprising a discrete message transmitted during a negotiation phase of a transaction that includes a plurality of modular elements whose individual integrity is protected by embedding cryptographic security codes within each of the modular elements; wherein the client computer is programmed to receive the digital coupon, protected by a cryptographic security code, from another computer.