Security Guide Controlling Access to Data Part III Controlling Access to Data Part III describes how to control access to data. Using Application Contexts to Retrieve User InformationAn application context stores user identification that can enable or prevent a user from accessing data in the database. Using Oracle Virtual Private Database to Control Data AccessOracle Virtual Private Database (VPD) enables you to filter users who access data. Using Transparent Sensitive Data ProtectionTransparent sensitive data protection enables you to find all table columns in a database that hold sensitive data. Encryption of Sensitive Credential Data in the Data DictionaryYou can encrypt sensitive credential information, such as passwords that are stored in the data dictionary. Securing and Isolating Resources Using DbNestYou can secure and isolate instance-level and operating system resources by using dbNest. Manually Encrypting DataYou can use the DBMS_CRYPTO PL/SQL package to manually encrypt data.