-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 21/07/12 18:02, Chris Ball wrote: > Hi, > > On Sat, Jul 21 2012, Michael Rogers wrote: >> Does anyone on the list know whether flash controller chips use >> journalling? I'm guessing they might because YAFFS does. > > I don't think so -- YAFFS is a filesystem, and the wear-leveling > algorithm on the controller only knows how to act on reads/writes > to individual blocks on the flash, so they're very different > layers. The flash controller isn't a replacement for a filesystem; > you still need to use one, and it may or may not be journaled. > > (Although the independence between wear-leveling algorithm and > filesystem isn't total; there's evidence that the vendors teach > their firmware how to handle writes to the Windows FAT cleanly.)
Thanks for the information Chris. Perhaps journalling was the wrong word for me to use - what I'm interested in is whether a forensic investigator can (partially) reconstruct the order in which the logical blocks of a flash device were updated. If so, TrueCrypt hidden volumes could be exposed. Each time YAFFS updates a logical block, it stores a numbered mapping from the logical block to a physical block. The numbers reveal the order of the updates. Do you know whether controller chips do something similar? Cheers, Michael -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) iQEcBAEBAgAGBQJQFmmJAAoJEBEET9GfxSfMMi8H/RR3xRubP3+ld7E+JIwqhmfi k1KE/lIHEKyJ7xlkGQzcCBG42TLcND+LlYQHk87QIyhnB/gFeIpEJUkLtBO3g+p8 aGCrAhYtRgTT+ULBN9EEQ2GdeSq6xL+JOd4l5xFLwtRgn/vDxvpjuN4FyPactDzK 02HFr867TO6BaVb+oVV1Q5EHjiv81O1fa6QHWY5yHIxN4sJDlxZQ+Mk/5Cnkvukd Ik3iypqnCZODrABsgHfnQHgCGpB88zKIjuiANMpaeke0fUWt+2bpb1reeQlFG/lX P1J2rqEs4Lsf/hDXIkOJARZmwlz7OsQgGK8VrOSiY9pkFhGp6kw9V/JLF+0fvlA= =DrW7 -----END PGP SIGNATURE----- _______________________________________________ liberationtech mailing list [email protected] Should you need to change your subscription options, please go to: https://mailman.stanford.edu/mailman/listinfo/liberationtech If you would like to receive a daily digest, click "yes" (once you click above) next to "would you like to receive list mail batched in a daily digest?" You will need the user name and password you receive from the list moderator in monthly reminders. You may ask for a reminder here: https://mailman.stanford.edu/mailman/listinfo/liberationtech Should you need immediate assistance, please contact the list moderator. Please don't forget to follow us on http://twitter.com/#!/Liberationtech
