PS1/2 Decrypting Files on PS2 ISO

[MarkAss]

Hello.
I was looking at Fullmetal Alchemist 3 to see if I could dump the text, but the files appear to be encrypted.
If I were to find the key in a memory dump, how would I go about using it to decrypt the file?

 

[NarutoClassics]

only thing that i hate from Racjin it's that fucking CFC.DIG/ .Raw files... it looks like we never will be able to open it