128w ago - Since the release of
PS3 Firmware v3.55 there is no sense in keeping the master key a secret any more - it has been released, along with unencrypted payloads, and a promise to release the source-code by PS3YES for a free
PSGrade PS3 downgrader.
Download:
PSGrade /
PSGrade PS3 Hex Codes
Of note, the downgrade hex will only work on PS3's with a firmware of 3.50 or below.
The same team which brought the PSN spoof for online support of jailbreaks now has also brought us a Free Downgrade HEX for the PS3! PS3YES has released un-encrypted HEX files for downloading.
They promise open-source code to be release soon, but find below pre-compiled HEX files:
PSGRADE AT90USB646-16Mhz Teensy++ 1.0
PSGRADE AT90USB1286-16Mhz Teensy++ 2.0
PSGRADE AT90USB1287-8Mhz
PSGRADE PS3YES
PSGRADE PS3YES AT90USB162-8mhz
PSGRADE PS3YES AT90USB162-16mhz
This is the last line from psgrade_ps3yes.hex
:10164E00FFFFFFFFFFFFFFFF3278572D9090D5ACC5
:0C165E00AEF903CA1AB65EF1B7694CDEA3
:00000001FF
Of note, The master key has been stated to be:
04 4E 61 1B A6 A6 E3 9A 98 CF 35 81 2C 80 68 C7 FC 5F 7A E8
Furthermore: A PS3YES flash update and PS3 Downgrade guide have been posted
here and PS3Key flashes have been posted
here.
PS3YES has stated, to quote:
"Our downgrade firmware is based on the PSGrade project, we will open the source soon.
Support for the following:
PS3YES AT90USB162 8mhz
PS3YES AT90USB162 16mhz
AT90USBKEY at90usb1287 8mhz
Teensy++ 1.0 at90usb646 16mhz
Teensy++ 2.0 at90usb1286 16mhz
Remember PS3YES were the first to release that PSN Hack that lasted a week on their Chinese forums!
Also sadly v3.55 is out so you can only use this great release to Downgrade v3.50 or LOWER firmwares!
NOTE: Importing the HEX to other devices using current payload converters will NOT work!"
graf_chokolo says: The key from KaKaRoTo for 0xAAAA dongle id is fine Just tested it by communicating directly with USB Dongle Authenticator from GameOS through DM VUART. Congratulations KaKaRoTo Good work!
and now square is dead to me! 
...
my 2 other fat ps3 with 4 usb port have laser issues
my slim will format if I donwgrade and some slim broke with the ylod
if it's because the 3.41 is modified why not just downgrade from that to 3.15 (or lower) and update to the legit 3.41
Can someone check this? Cheers
The guide: http://www.ps3news.com/forums/ps3-guides-tutorials/how-turn-ps3-demo-kiosk-consoles-into-retail-jailbreak-115834.html
http://www.ps3news.com/ps3-hacks-jailbreak/videos-debug-firmware-on-retail-ps3-via-ps-downgrade-demo/
I dont see how as the retail 2.15 doesnt even work to begin with...