You need to place the .rap file in a certain directory, I think it is \Rpcs3\dev_hdd0\home\00000001\exdata, but not sure. Then decryption will work, but the game will probably not display anything since the emulator is very unfinished...
Asus N55SF, i7-2670QM (~2,8 ghz under typical load), GeForce GT 555M (only OpenGL)