secure file deletion/SECRM support for JFFS2 and UBIFS

[Richard Weinberger]

Chris,

On Wed, Apr 27, 2016 at 7:07 AM, Chris Packham
<Chris.Packham at alliedtelesis.co.nz> wrote:
> Hi,
>
> We have a customer request for "secure file deletion" for our embedded
> devices (kernel version 4.4.6). The first device is running JFFS2 on
> parallel NOR flash but we expect to see the same requirement pop up on
> our newer devices running UBIFS on top of NAND.
>
> I found a couple of old threads related to UBIFS but they all appear to
> have fallen silent. Nothing really for JFFS2.
>
> For our application we're not really concerned about defeating
> determined attackers who have access to the device and hardware that can
> do detailed analysis on the transistors that make up the chip. But we
> are trying to protect against casual attackers (or recipients of
> re-furbished hardware) who can run 'dd'.
>
> So I think for us it'd be enough to implement chattr +s and have the
> file's data over written with a fixed value (e.g 0 for NOR flash) when
> it's blocks are added to the garbage collection list.
>
> Is that something people on this list would be interested in? I realize
> JFFS2 is kind of in a twilight phase but we're really not able to
> migrate some customers away from it.

This is definitely a nice feature.
But please keep in mind that you can overwrite data on flash. :-)

-- 
Thanks,
//richard