N72AP

This is the 2nd Generation iPod Touch

Model: n72ap Application Processor (OS Chip): s5l8720x

Decryption of it's Ramdisks, iBoot, LLB, Kernel, and friends

The application processor has a new GID key in it, so you can't decrypt kbags from it on any other device than itself. So, you pretty much will not even be able to make a pwned IPSW, let alone decrypt the RootFS, unless a low level (like, bootrom/kernel/iBoot) exploit is found. From there, it can be used to run code to decrypt the kbags so that we can in turn decrypt the files, and then to run code to actually pwn the device.