USB MSD bootloader application protection

Hello Guys,

Im working with usb mass storage device boot loader. In which i can able to program my application using pendrive. The code for bootloader is available and working fine.
In this case i have to past .hex file of my application to pendrive and rename it as image.hex, but any one can use my application hex file and load into another device using bootloader which is easily available.
I want to provide protection so that my application not worth until they have my special bootloader.
There is some methods using data encryption but i dont want to use it.

Im thinking of writing some value to specific location in program flash memory in bootloader, and when my application boot it will check that value and if it is found then only my application work.
Is it possible.
Im using pic32mx440f512h cpu.

Thnks.

https://www.microchip.com/forums/m675699.aspx

In this post you can see how to use shared memory by changing linker script

So by using this initialize some memory with fixed value and check those values in application.

Using this can i provide protection?
or using some other method anyone can ***** my code?