What is the best way to encrypt columns in SQL Server 2005 Express edition so that no one can steal our database design?
Thanks
there is no best way to do this.
if you obfuscate them you give yourself a lot of pain when debugging. you'll have to change all the queries. there's no good tool for this.
not to mention that the potential dba who'll might have to look at it and tune is going to be lost.
It's probably hard to accpet but your database design isn't something brilliant and new. I'm sure someone else has done it before. So there's no real need to protect it.
I suggest you set permissions for data access, not obfuscate schema. Schema isn't important, data is.
You could encrypt certain db objects like sprocs and views but this is also useless because there are not too hard ways of cracking it.