The keys are not required to access the binary. There is no encryption; the keys are just to verify that the OS image hasn't been corrupted. The entire binary has always been completely accessible from both the PC side (before transferring) as well as on the calculator. Furthermore, the community has had the ability to load its own operating systems on the TI-83 Plus since 2002. TI had stated in 2004 that they had no problem with independent third-party OSes being loaded, as long as (understandably) no one distributed modified TI OS files. The only new development here is that third-party operating systems can now be loaded onto the calculators without any hacks or preparation. In other words, they can be loaded in a user-friendly manner like the TI OS is loaded, and transmitted from calculator-to-calculator without having to run a special program beforehand. This is a huge deal in gaining acceptance for third-party operating systems, because end users do not want to have to pull out a battery during validation or run a strange program before loading the OS. They'd rather just click and be done.