DLC Decryption

[Hykem]

So, I've disappeared again, but this time I have a good excuse.
I've finally cracked the rest of the NPDRM encryption.

Turns out, JuanNadie's findings on the PS3 are applicable to the PSP too.
I've found the same encryption keys used in the PS3 in the PSP's npdrm.prx module.
I'm now currently able to fully decrypt EDAT and SPRX files, but only by using a valid DLC license (.rif file), an act.dat file from a real PSP and the PSP's OpenPSID. I'm now researching how these files are generated (scePcactAuth1BB and scePcactAuth2BB) in order to generate a custom act.dat file and the proper license files using a dummy OpenPSID.

I've updated the main post with the new findings.