sql express 2005 security

Hi All,

I'm going to implement a standalone solution to my company's partners, which
is a VB.NET application with some $$ calculations.
Some rate data are sensitive and we choose to use sql server express 2005 as
local database engine.

My concern is that, how can I protect my id & password to access sql
express?
At least I need to code it inside VB.NET SQLConnection in order to access
the rate, and the code in VB.NET could be reversable, I afraid if someone
can hack into the code and discover the login credential.

Is there a way to prevent it?

Thanks.


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