Ailurus fulgens wrote:
> saving a key on the sdcard is not neccessary, we just have to finally
> implement the keyboard. or if that isnt done, we could use a sequence
> of key presses.
No, that wouldn't be an option. If you first have to enter a password
before you can take pictures, then the camera becomes unusable. The best
way would be, to generate a random password after power on for a symmetric
encryption algorithm like AES, encrypt this password with a public key algorithm
(the public key can be stored on the SD card) and then add the public
key together with the encrypted AES key as comment in the jpg header.
Also the encrypted jpg data is stored as comment only in the jpg file.
As actual jpg data a small picture is added, which only displays:
"This picture is encrypted". This way the SD card can be read on any
PC, but all you see is a picture with "This picture is encrypted". A play back
in the camera is only possible for pictures taken since the last power on
(because this AES key is still available in the camera), for any older
pictures you also get just a picture with "This picture is encrypted".
But for a start it would be sufficient to do it without the pubic key
encryption by generating new passwords by applying a hash function to the
old password.
> anyhows, it IS possible, but somebody gotta do it
That's easy to do for the camera manufacturer, but I don't know whether
it can be done within the CHDK project.
> btw:
http://www.canon.co.jp/imaging/osk/osk-e3/index.html> it should be possible doing something like this. information about
> this osk-e3 is very rare in the internet. i wonder why Wink
There is no information on this Canon web page which encryption they
use so you shouldn't trust it too much.