As the private master keys have been leaked, new homebrew and pirate games can be signed freely by anyone. If the new PS3 doesn't block all the old PS3 games (signed with the old private master key), it cannot block the new homebrew and pirated games either (signed with the same old private master key). You can't distinguish the old legal software from the pirated/homebrew ones.
The Xbox 360 security hole was much less minor, so they could patch it. The PS3 hole revealed all the private signing keys, so there's pretty much nothing Sony can do to make the platform secure anymore.
The reason for asymmetric cryptography is that you do not need to access the private key to check the signatures. The private key key can be locked to a very secure place inside Sony offices. However Sony did a major mistake by forgetting to seed their random generator properly, and the private keys could be calculated from the public ones found inside the console... Really stupid mistake indeed.
sorry my understanding of cryptography not good.
btw i mean using new key with proper random number on new ps3.
something like : "New" PS3 on production is made with new keys with proper random number. Or whatever measures to make its secure. And still allow loading the games with the "compromised" key.
New games use maybe 2 executeable (2 EBOOT? 2 SELF?). "A" with the current key for old console to run, "B" with new key to be run on new console.
"new" PS3 will do a whitelist/check for new games.
on "new" ps3 = old game allowed all (hmm pirated games that resigned maybe still work..) . But on new games, "new" ps3 will check both executeable A and B.
even if hackers resign the "A", the "B" are using the new safe key. "New" PS3 need both of this to be valid to run the game.
On old PS3, can run the game as usual using the usual executeable.
old PS3 still can play new games. also Old PS3 still can play pirated new games.
Sony release 2 version of firmware update.
version A - for "old" ps3
Version B - is the new secure firmware, un-decryptable, for "new" PS3. The "new" ps3 also only accept this "B" firmware.
so sony still giving support to old ps3 to work. But pirates cant do harm to new PS3. But yeah this is not a really good solution for console that already huge userbase...
basically the current userbase will able to pirate all they want.
only the new buyer that can't pirate.