ocr: User ID Subsystem Physically Insecure e.9: SmartCard External Remote Link Network Client PC Encryptor Internet e.g. Link Encryptor Firewall Router UserID Subsystem Local Client PC Authentication Access Contiol Physically Agent Server Server Secuire: Intranet Application Servor Data Warehouse Data Data Dati Server Server Server Figure 1. Atypical secunty architecture for. an enterprise data warehouse.