Date field encryption using Dbms_Obfuscation_Toolkit.DESENCRYPT

Question

Hi,
I need to encrypt the date field in the table using Dbms_Obfuscation_Toolkit.DESENCRYPT .
This is an table is an existing table and is accessed by many interfaces, so we cannot change the column type of this date field.
Is there a possibility of encrypting the date field and store it in the same column (DATE type).
And access this using Dbms_Obfuscation_Toolkit.DESDECRYPT.
We are using Oracle 11.2.0.2.0.
Thanks in advance.
Agathya

Answer 1

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Is there a possibility of encrypting the date field and store it in the same column (DATE type).
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No - the DESENCRYPT procedure returns a RAW value which can't be stored in a DATE column.
See DESENCRYPT Procedures and Functions in Chapter 82 (DBMS_OBFUSCATION_TOOLKIT) of the PL/SQl Packages and Types Doc
http://docs.oracle.com/cd/B28359_01/appdev.111/b28419/d_obtool.htm#i997215
For what you want to do just use the ENCRYPT option of the CREATE TABLE or ALTER TABLE statements.
See Using Transparent Data Encryption in the Advanced Security Admin Guide
http://docs.oracle.com/cd/B28359_01/network.111/b28530/asotrans.htm#BABJJAIG
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3.2 Using Transparent Data Encryption
The following steps discuss using transparent data encryption:
•Enabling Transparent Data Encryption
•Setting and Resetting theMaster Encryption Key
•Opening the Encrypted Wallet
•Creating Tables with Encrypted Columns
•Encrypting Columns in Existing Tables
•Creating an Index on an Encrypted Column
•Adding or Removing Salt from an Encrypted Column
•Changing the Encryption Key or Algorithm for Tables Containing Encrypted Columns
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Section 3.2.5.2 Encrypting an Unencrypted Column shows the ALTER TABLE statement for encrypting an existing column - this would leave the column as a DATE and you would work with it normally
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3.2.5.2 Encrypting an Unencrypted Column
To encrypt an unencrypted column, use the ALTER TABLE MODIFY command, specifying the unencrypted column with the ENCRYPT clause. Example 3-7 encrypts the first_name column in the employee table.
Example 3-7 Encrypting an Unencrypted Column
ALTER TABLE employee MODIFY (first_name ENCRYPT);
The first_name column is encrypted with the default AES192 algorithm. Salt is added to the data, by default.
You can choose to encrypt the column using a different algorithm. You can also specify NO SALT, if you wish to index the column.