Thread: Signed codes - why not possible?

Hi guys,
There is something I have not really understood.
One year ago they said it would be possible to sign any code in order to be able running it on the PS3.
Now it's not possible anymore, for example some CFW 4.00 (or let's say pseudo-CFW 4.00)
describe "install package" files is available but it's not possible to run unsigned code.
I mean old games like Ninja Gaiden Sigma can be started, so why can't a new manager get started?
How does Sony know it's not signed?
Sure it might be a problem to create a new real custom firmware - I can understand that, but I cannot understand how the PS3 knows it's some other code.

Hope you guys can explain.

sony has those .edat files, which are encrypted with DRM (Digital Rights Management) keys...but i m not a hacker, i cannot go further...

I wasn't aware people are playing games on 4.00. Install is one thing but to have it play is another. Rumor and actually seeing it is another also.

How does Sony know it's not signed?

Don't you think Sony would be out of business if that was public knowledge by now? Billion dollar companies with smart people are suppose to make it hard. I don't know. Seems like you need a dev or someone that really knows something about Sony codes.... which I'm guessing most us wouldn't want to get into.

Ok there are two types of key sets, private and public.

private keys-used to sign, specific to each console (can't be changed due to hardware)

public keys-used to decrypt, games are signed with these (can be changed with FW update from $ony)

The public keys can be changed and Sony did that, now we don't have them and to the ps3 everything that comes from the game is just gibberish.


If you want more info on it, and I recommend that if you want to understand the stuff that's been going on check the ps3devwiki.

Thanks for your replies.
Okay so you think Sony made such edat files for any kind of games?
Imagine you download an old demo of some game.
It runs without no problems.
Any managers won't run.
Okay it makes sense that there are new files that are needed.
Well, it must have been a hell of a work if Sony really updated all games/demos.

the console knows it's signed properly because it's on a disk.
or is on a whitelist of old programs.
or the .elf is signed in a different manner with retail games.