Patent ID: 7275057

Claim:
A method for reducing the amount of data to be exchanged in a business to business electronic commerce system that exchanges documents between at least two computers connected via a communication network, the method comprising the steps of: at a source computer, retrieving from a counterpart management database in the source computer a counterpart identifier to check whether a destination computer is capable of receiving a difference document; at the source computer, retrieving from a transmission history database a transmitted source document that is similar to the document, and has been transmitted to the destination computer; generating the difference document between the document and the transmitted source document; transmitting the difference document from the source computer to the destination computer; at the destination computer, retrieving from a reception history database a received source document that is a basis of the difference document received from the source computer; and restoring the document from the received source document and the difference document; the method further comprising: switching between transmitting the difference document and transmitting the document depending on whether the destination computer is capable of processing difference documents, wherein the difference document is transmitted from the source computer to the destination computer only when the destination computer is capable of processing difference documents, and the document is transmitted from the source computer to the destination computer when the destination computer is disabled to process difference documents, and wherein the destination computer conforms to business-to-business standard specifications.