A method of data transmission including receiving a request for data over an Internet, by a data provider; obtaining data, in response to the request, at the data provider; applying a quality assurance procedure to the obtained data, responsive to the request, at the provider and other than any virus scanning of said data; and transmitting the data over the Internet responsive to the assurance. Preferably, the quality assurance procedure includes assuring that the data is pre-approved for transmission. Preferably, the procedure includes verifying a digital signature of the data.