you luksHeaderBackup the header like in the article and then fill the first n bits of the device with random 0 and 1's
this is an example offset from luks2 (do a luksDump) offset: 16777216 [bytes] most probably the offset is the same everywhere but make sure yourself. You can restore the header later.
I personally wouldnt do it like this. at least the part about attaching it to an img, ok.. but if you do, why not wrapping the data in some good protection with gpg for example. always keep this header secret, thats the whole point of detaching it anyway
Re: Separate header
this is an example offset from luks2 (do a luksDump) offset: 16777216 [bytes]
most probably the offset is the same everywhere but make sure yourself. You can restore the header later.
I personally wouldnt do it like this. at least the part about attaching it to an img, ok.. but if you do, why not wrapping the data in some good protection with gpg for example. always keep this header secret, thats the whole point of detaching it anyway