This last week in August we have new update on TheiPhoneWiki for Firmware Keys 32bits ios9.3.4 . New keys were added for developers are working on this latest firmware.
(File System, Ramdisk, IVs, Kernel, iBOOT and other keys for x32 devices iPhone 4S, 5 and 5C. this keys will let you decrypt apple firmware to create custom firmware.