Differentiate Between Whether Stored Procedure A Is Executed Inside Query Analyzer Or Executed Inside System Application Itself.

Just wonder whether is there any indicator or system parameters that can indicate whether stored procedure A is executed inside query analyzer or executed inside application itself so that if execution is done inside query analyzer then i can block it from being executed/retrieve sensitive data from it?

What i'm want to do is to block someone executing stored procedure using query analyzer and retrieve its sensitive results.
Stored procedure A has been granted execution for public user but inside application, it will prompt access denied message if particular user has no rights to use system although knew public user name and password. Because there is second layer of user validation inside system application.

However inside query analyzer, there is no way control execution of stored procedure A it as user knew the public user name and password.

Looking forward for replies from expert here. Thanks in advance.

Note: Hope my explaination here clearly describe my current problems.