I am in the final stages of development for my Revit plugin. This plugin is programmed in C#, and distributed via a DLL. One of the DLLs is an encrypted SQLite database (with proprietary data) that is in the form of a DLL. Currently, in development stages, the decryption key for the SQLite database is hardcoded in my main DLL (the program's DLL). For distribution, since DLLs are easily decompilable, I am in need of a new method to decrypt the DLL. My solution is to send our decryption keys from our servers securely to the host's computer.I was looking in POST, thinking it was more secure than GET, but upon research, it appears it's similarly insecure, only more obscure than GET. I also looked into HTTPS, but Hostgator requires extra money for HTTPS use.I am in need of some advice - are there any custom solutions I can do to implement this? 
Safest way (i.e. HTTPS, POST, PGP) to send decryption keys through the web?
encryption