I always wondered how my Mac could connect to the internet when the recovery partition is booted and my main system partition is locked (filevault2).
Some googling revealed today (e.g. here, here, and also on askdifferent) that the WiFi password is apparently stored in NVRAM and that needs to be reset to remove the password. As a security conscious person this is unacceptable to me. When using Full Disk Encryption (i. e. Filevault2) I expect the system to be safe, also against my network.
So is there a way to prevent OS X from making the password available in the recovery partition? I am not sure how or when it gets into NVRAM in the first place.
The NVRAM contains the following keys: (
nvram -p) :
BootCampHD SystemAudioVolume SystemAudioVolumeDB aht-results backlight-level bluetoothActiveControllerInfo bluetoothInternalControllerInfo boot-gamma efi-apple-recovery efi-boot-device efi-boot-device-data fmm-computer-name good-samaritan-message gpu-policy prev-lang:kbd
efi-boot-device look like they could contain encrypted data.