Uniquely identify a SQL Server computer via T-SQL

We are working on a licensing system for a client-server application where the only server component is a database (no application server). We would like to issue licenses to a particular server that cannot be installed on any other server or transferred via backup/restore. The idea is to generate a unqiue identifier via a T-SQL query and then use public/private signing to return an activation token that works only for that identifier.

Is there a way to uniquely identify a SQL Server, in a repeatable way, using only T-SQL (withou开发者_高级运维t a CLR stored proc or function)? For example, is there some retrievable, unique value that is created when the instance is installed?

Edit: Maybe the MAC part of NEWSEQUENTIALID() would work (see this method). If the system fails over in a cluster/failover setup, or if the primary LAN adapter is changed, it could enter a "grace period" during which it will continue to operate until re-activated on the new hardware. The question is whether this is "unique enough."

Even if you get a unique ID a potential problem is validation at T-SQL. The database is not validated. What if they hack the T-SQL and remove the activation part. Does the customer use T-SQL directly or do you have a client application. If you have a client application then why is CLR not an option. It was crack-able but I worked with an application that generated a hash of server name on the install and stored it in the database. Then the client would compare the stored hash to the dynamic hash to determine if it was on another server. Problem was if the server name was the same then it could be beat and the hash algorithm was on the client application so with effort it could be exposed.

Adian I wish I could thank you for answering my questions.

If you look in sysObjects and other systems tables/views I think you can find something to uniquely identify a server and database. Like on a restore to another server you have to delete the user and and recreate the user even though the name is the same the internal id is different. If they restored the master and application database they might be able to make everything identical but they would have to know to do that. On the base install SQL may generate a unique id somewhere as it makes sense Microsoft would want a unique id for replication, other features, and licensing.