Proposal: Personal Data Encryption (maybe SoC?)
jjpfeifferjr at comcast.net
Wed Mar 21 20:41:01 CET 2007
Tim Newsom writes:
>On Wed, 21 Mar 2007 9:34, Joe Pfeiffer wrote:
>> Tobias Gruetzmacher writes:
>> Right -- these look like good approaches, but to a different problem.
>/please excuse my direct manner.. Its just how I write (smile)
Likewise -- it's hard to see somebody smile by email, and I never
intend to offend.
>What do you mean by different problem? Maybe I don't fully
Near as I can tell, these approaches require you to partition up your
maching into an unencrypted area and an encrypted jail -- maybe
through a physically separate device, maybe through a separate
partition, maybe through a file that's mounted as a filesystem. I
don't want that -- I want to be able to specify encryption on a
file-by-file basis, in a manner that comes as close as possible to
being generic across all applications without code changes to those
At the moment, I'm wandering around the source code for __libc_read() and
__libc_write() to see if there's a good way to hijack a program's
read() and write() calls, so if they are to a file that's marked as
encrypted the data can go through encrypt() on the way....
>The way I see it you have a few interoperating components... Dbus can
>be the primary transport mechanism, some reader plugin which abstracts
>the actual source of the data.. Be it the filesystem or a file which
>sits on the filesystem that has its own filesystem.. Or a dbfile system
>(I have not heard much about that recently)... A writer plugin which
>does pretty much the same thing, but for writing and not reading.. Maybe
>they are even the same plugin.. /shrug
>Then you have some authenticating system which allows various methods of
>authenticating a user.. Be it fingerprint reader or pincode or whatever
>based on the currently selected provider/plugin... And you have the
>At the lowest level is the encryption/decryption system.. Right above
>the filesystem somewhere.
I think we agree here; I'm just trying to avoid having it
>Now, when the phone is idle long enough or locked and a user tries to do
>something, the currently configured login / unlock / whatever you want
>to call it authentication plugin is activated and asks for the required
>information / gesture / whatever.
>Once obtained the user is granted whatever rights they configured for
>that action.. By default it can be nothing or a pincode and the default
>level can also be set to wide open, no encryption and full access.
>That's the state of almost every phone on the market right?
As far as I know...
>Ok.. So an advanced users phone may have 3 or 4 levels of authentication
>and access / encryption.. Maybe even different algorithms are used. Who
>knows? When they log in they probably set it to the lowest level of
>access.. The notes application can read plain text with no problems and
>any unsecured data is visible.. Including contacts, notes, pictures,
>Now suppose this individual decides to read an encrypted file or runs an
>application configured to access an encrypted file or file system.. The
>authentication system would then ask for additional authentication and
>once granted handle the key pass to the decryption system / whatever to
>read the file.
>Now I don't have any experience with truecrypt or LUKS yet.. But they
>were mentioned along with encryptfs etc as a means of handling the
>Maybe you can help me with where I missed out on the problem so that I
>can get my head around it? (Grin) I would love to make sure I fully
>understand what you are saying.
Hope my notes above are helpful...
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