Originally Posted by TheMathMan
That's what i figured.
I was reading one of the rooting threads and someone was saying that once he had 0x1 he always get a secure error when trying to flash the radio.
If it's fine then I'll just CF Autoroot rather than fussing with towelroot
I think he must be confused about the changes that occurred with the 4.3+ OS. The bootloader after 4.3 is more restrictive and will sometimes balk at flashing a radio, but it does so for both 0x0 and 0x1 flags, so it's a moot point. The workaround to that is, if necessary, is to flash a full firmware image which will succeed in updating the radio even with a 0x1 flag.
He probably incremented his Knox flag right around the time 4.3 came out and doesn't realize what is really going on. That behaviour i.e. bootloader authorization failures appears to vary by carrier and radio version FWIW. But again, in the worst case, you can still update your radio by flashing a full firmware image.
You could preserve your Knox flag by using Towel root. But you wouldn't be able to use a custom recovery or kernel without incrementing the flag and I for one would not give up either.
The only things that the flag really effect are the secure storage feature that few use and the supposed effect on your warranty. But it's usually Samsung direct trying to deny a warranty claim due to a 0x1 flag. Most carriers don't care about Knox, so claims made through carriers are typically unaffected. And Samsung can't enforce that prejudice in the EU either.
The radio (aka modem) is the firmware component that enables your phone to communicate with the carrier's network.