I have developed a software that opens encrypted files. the files are Encrypted with the key generated from a Mixture of Device Hard Disc Serial and Mac ID In the server side.
In Order To prevent that File to be Opened on any other Device, In Client Software I Generate the same key from Device Hard Disc Serial and Mac ID too, and Decrypt the file with that Key.
Is it the correct way to limit unauthorized computers to open the file? If yes, what if someone debugs the assembly code of my software and Understand the generated key?