I Found this in PSP-Hacks
Posted by greg
Check this outÖ an email from Patrick!
GmDude66 from pspupdates has managed to fully decrypt firmware 2.80. Below is a changelog of files that were added/changed. And yes, 2.80 uses the same encryption key as 2.70 did.
netfront.skn changed to netfront.rc
f:\dh\280\ipl and f:\dh\271\iplcomparrison
psp_ipl.bin changed to psp_nandipl.bin
psp_ipl.bin_p1 changed to psp_nandipl.bin_p1
psp_ipl.bin_p2_040F0000 changed to psp_nandipl.bin_p2_040F00 00
psp_ipl.bin_p3 changed to psp_nandipl.bin_p3
Well that didnít take long at all - please note 2.80 has yet to be emulated with DevHook