Need a modification in my C code

i have source code of the project which is designed to run in cpu and i need to modify the code to run in GPU and if it has pause and resume functionality even after i turn off the pc and also on the pc means if it resume from where it has left the previous stage means it will be better.i am expecting good skilled professional who has experience in AES256CBC decryption of ckey and mkey means it will be good.you can see the source code here
https://github.com/albertobsd/crackBTCwallet

finally it gives the WIF of the wallet.dat file means it will good and also the program shows the estimated time of completion while program running means i feel happy.