Distribute Data Securely in SSExpress

I would like to distribute some data in SqlServer Express which only my application can read from.

My question is - is it possible to secure a database so that only a specified user would have read/write permissions. Even the sa acount should not have the permission to read or write to the database although it would retain the right to drop the database.

One option I believe is to encrypt the data but I would prefer not to incur the performance penalty associated with this.

Any insights would be appreciated.

Thanks

This topic has been previously discussed in the following thread:

http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=52094&SiteID=1

Thanks
Laurentiu