Binwalk on nandchip[ TM1602A, SB6183, ]

[Bm599]

First of all to Determine if your file is encrypted Run binwalk -E (Filename) This will give you a graph view of the layers of the file if the graph looks like a Straight  line it is indeed Encrypted if the grap goes up and down its not 

Not Encrypted :
   

Encrypted :