Oracle database has enhanced security features such as Transparent Data Encryption to ensure the integrity of data.Transparent data encryption can be implemented by configuring Oracle wallet.We need to open the oracle wallet for the database to use transparent data encryption feature.
When this feature is enabled information written to data files, redo logs, undo logs, SGA buffer caches are encrypted.
To open the wallet, database should be in mounted state and not open
SQL> alter system set encryption wallet open authenticated by password;
In case of RAC wallet can be opened at each instance level.
To close the wallet, issue the command at each instance level :
SQL> alter system set encryption wallet close;