Connection string: which one is more secure Linq to Sql or Entity Framework

Question

Hello,

I have to make a new windows project using remote sql server database. To make a decision regarding the choice between Linq to Sql and the Entity Framework, I initially created two identical test projects the unique difference was data access technology, to compare the performance between these two technologies, I noticed that the EF project is about 4 times slower.

Now I'd like to be helped on the question of security:

Having to use an encryption of the connection string in the App.config file, I wonder if there would still be vulnerabilities in the use of data models. Dbml or. Edmx

Also I wonder how to configure remote (Windows Server / SQL Server 2008) and the local (Windows 7 / application) to establish  connection with integrated security (Windows).

Thanks in advance