The game is using standard aes-128-cbc encryption, except that the key and IV are statically generated at runtime. Attached script was tested on mobile version of Dragon Quest Rivals Ace v3.8.0 and samples from the first post.
I suppose tga textures are using ETC1 compression (for more info read here
Script is updated to automatically decompress decrypted assets in case if they're compressed (like samples from the first post).Update 2:
Updated script can now convert/fix tga textures for usage with etc1tool from Android SDK platform tools, available here
. Simply run script on already decrypted and decompressed texture and it will be replaced with fixed one, just don't forget to launch quickbms with "-w" option to allow write operations.
You can request AES keys on rin forums
(the list with keys is also there)
AES keys finder and latest UE4 bms scripts: in this post