Hi,
I would like to implement encryption to my sql server data without major change to my application. I was thinking to create view for my table. In INSTEAD OF UPDATE trigger, I will check if my particular sensitive columns are updated. If so, I will encrypt it and save it. The other un-sensitive columns must always be saved to table.

How to do this?
Do you think I should use AFTER TRIGGER instead of INSTEAD OF TRIGGER?

** Update: I am using SQL Server 2005

Thank you