Patent attributes
A system and method allows for paperless billing transaction document exchanges between two parties to a sales transaction, with inherent document verification. In an embodiment, the system and method first encrypts the transaction document data according to a password which itself depends on unique transaction data in a particular sales document. The system and method then employs the unique data values to create a first 2-D barcode which directly represents the document data; and to create a second 2-D barcode which represents the encrypted document data. The two matrix codes are overlapped on a cell-by-cell basis into a single visual representation, employing multiple colors for different combinations of overlapped cells. At a receiving end, the two original matrix codes can be separated by extracting the two black and white 2-D barcodes from the combined color code. The data integrity of the received data is confirmed by checking that the encrypted 2-D barcode is consistent with the plaintext 2-D barcode. Additional methods are employed to attach secure, merged biometric image signatures, such as merged fingerprint images, to the merged 2-D barcode form of the transaction document.