Original Post
Hi there, I programming an automatic answering for protecting my products(Game,Application,...) for desinning this protection system,I give a code(serial number) from Hard Disk. Hard Disk have code with 40 number lengh. I must decrease this code to 9 number.(Answering Machine limitation!) I want write a code generator for this protection system. Can you introduce me the best way for reaching this purpose with high security ?