Patent attributes
A system that communicates information is described. During operation, this system receives an encryption key through a first wireless communication technique, wherein the first wireless communication technique includes near field communication. Then, the system communicates a document through a second wireless communication technique, where the document is associated with a financial transaction being conducted with a commercial establishment. Next, the system receives encrypted information through the second wireless communication technique, where the encrypted information is, at least in part, encrypted using the encryption key, and where the second wireless communication technique includes a technique other than near field communication.