Pause Game during Game Center Authenticate?

Questions & Answers
1

How can I pause the game During the Game Center Authentication Process.

Sometimes the process (depending on internet connection I suppose) takes so long by the time I start the game it interrupts game play and the game continues to play behind the pop up, forcing the player to watch as the character helplessly dies.

2

Have you tried setting Time.timeScale equal to 0?
That is generally the easiest way to pause a game since everything moving should be based on Time.deltaTime.
Once it has finished loading, set Time.timeScale back to 1.