16. The method of claim 14 , further comprising applying a key cluster operation to the shuffled array to form a new shuffled array.
16. The method of claim 14 , further comprising applying a key cluster operation to the shuffled array to form a new shuffled array. 18. The method of claim 16 , wherein applying a key cluster operation comprises identifying a subset of characters in the shuffled array and concatenating the subset of characters to the end of the shuffled array to form the new shuffled array.