(adsbygoogle = window.adsbygoogle || []).push({}); what i want to no and have been thinking this through for a long time

i no the ps3 checks a update server upon boot to see wether there is a new update avaliable

but how does the ps3 no that this update is legit i mean in terms of keys etc

like when we try to install cfw on anything higher than 3.55 u get errors relating to keys being blocked

now does the current firmware hold keys relating to the next firmware?