TDE will handle the specific question you posted but probably not the underlying intent. There really is no comprehensive way to protect your Intellectual Property (IP) if you're deploying the database to the client site. Anyone who is a local admin on the machine where SQL Server is being hosted can enter the database as a sysadmin if they know to start SQL Server in single-user mode. Encrypting the database with TDE will protect the data at rest, i.e. if someone takes the mdf or a backup of the database to another server they will not be able to access to it without knowledge of the key infrastructure. If you want to protect your IP you'll need to host the database for the solution yourself or move to a hosted solution like SQL Azure.