Possibly offtopic : Binary only driver

[Stefan Sonnenberg-Carstens]

Dear list,
I work for a german company which aims now
to bring a Windows client  to the
linux world due to repeated requests of our customers.
The development is in early stage and I'm gathering
information to create an install package for the
customers.
The problem is that the software depends on a piece
of usb hardware which does some encrpytion.
I get the driver by signing an NDA and therefor
we can't release it openly.
The problem I have now, that the driver needs to be
rebuild with every new kernel version, which is released.
Is there a way to avoid that ?
I have developed kernel drivers for Linux for 2.2.x kernels,
but things seem to have changed ....

Any help is appreciated,
Stefan Sonnenberg

P.S.:
I think many problems have such a problem,
and I believe that Linux success in the customer world
depends on solving such problems.