Can we (if YES, How) modify/alter the table definition to convert a column datatype to the encripted form say

ssn varchar(124) for bit data);
set encryption password = 'Ben123';

from the existing definition of that column

ssn varchar(124)

Response is highly appriciated...

DB2 v7.2 introduced the encrypt/decrypt functions.

Example from the V8 information Center:

SET ENCRYPTION PASSWORD = 'Ben123';
INSERT INTO EMP(SSN) VALUES ENCRYPT('289-46-8832');
SELECT DECRYPT_CHAR(SSN)
FROM EMP;

Hope this helps.