Data Encryption Oracle

Question

Hi,
I would like to know the best practice which we can adopt for data encryption .
We have an Oracle Database Table with a sensitive data in one field.We would like to encrypt the data in this field and store it. When the application retrieves this,it shows the data only for privileged users.Can you suggest the best encryption method which can be used for this
Thanks,
SSN

Answer 1

A new feature in Oracle Database 10g Release 2 lets you do just that..
To encrypt columns using Transparent Data Encryption(TDE), all you need to do is add a simple clause—ENCRYPT—to the column definition. Before you do that, however, you must decide which type of encryption and key length to use.
On a regular schema, suppose you have a table of account holders as follows
ACC_NO NUMBER
ACC_NAME VARCHAR2(30)
SSN VARCHAR2(9)
Currently, the table has all data in clear text. You want to convert the column SSN, which holds the Social Security Number, to be stored as encrypted. You can issue
alter table accounts modify (ssn encrypt);
This statement does two things:
1.It creates an encryption key for the table. If you change another column in the same table to use the encrypted format, the same table key will be used.
2.It converts all values in the column to encrypted format.
This statement doesn't change the data type or the size of the column, nor does it create a trigger or a view.
By default, the algorithm AES with 192-bit key is used to encrypt. You can also choose a different algorithm by specifying the appropriate additional clause in the command. For instance, to use 128-bit AES encryption, you can use
alter table accounts modify (ssn encrypt using 'AES128');
You can use AES128, AES192, AES256, or 3DES168 (168-bit Triple DES algorithm) as clauses. The values are self-explanatory; for instance, AES256 is for Advanced Encryption Standard algorithm with 256-bit key.
After encrypting the column, you'll see the following when you describe the table:
SQL> desc accounts
Name     Null?     Type
ACC_NO          NUMBER
ACC_NAME          VARCHAR2(30)
SSN          VARCHAR2(9) ENCRYPT