In my previous question I learnt something about Group Temporal Key (GTK), but after searching the internet I have another questions:
1. How is Group Master Key (GMK) derived? What is GMK derived from (which formula describes the derivation of GMK)?
2. How is Group Temporal Key (GTK) derived? Is GTK derived only from GMK or do I need more factors than only GMK?
3. How many bits does GMK have?
4. How is Group Encryption Key (GEK) derived? Is GEK derived only from GTK or do I need more factors than only GTK?
5. How many bits does GEK have?
6. Which sets of characters can be used in Group Keys (GMK, GTK, GEK)? Do these keys contain lowercase, uppercase, digits and special signs? Can't these keys use any of the above specified sets?