A system for transmitting information between a seller and a supplier uses a web services application to interface between a seller application and the supplier's server. The web services application uses a proxy to transmit information from the web services application to the supplier's server in a secure and reliable manner. The information is transmitted via HTTP using SOAP messages that conform to WSDL. In such a manner, the web services application can transmit selected information to the supplier's server, without any need to re-key redundant information. The proxy provides various services, such as encryption/decryption, digital signing, non-repudiation services, reporting capabilities, and software updating capabilities.