a registry entry that only changes after a reset?

  • Thread starter Thread starter casey chesnut
  • Start date Start date
C

casey chesnut

[not directly related to CF]

is there a system registry that changes after each time the device has been
reset?
the registry entry would have to be on most CE devices (an API call would
work too).
i need something like this for generating key material for security.
the value should change after a reset, and only after a reset,

so that 2 different processes running at the same time could generate the
same key.
after a reset, the next time both processes run, they should be able to
generate identical keys again;
although that key will be different then the one they generated last time.

also, time will not work, because it could be left powered on for multiple
days.

Thanks,
casey
http://www.brains-N-brawn.com
 
Casey,

Don't forget that it doesn't necessarily increment on all devices every time
(because they may not persist their registry just because the BootCount
changed).

Paul T.

casey chesnut said:
Chris Tacke pointed me to HKEY_LOCAL_MACHINE/Comm/BootCount
Thanks

[not directly related to CF]

is there a system registry that changes after each time the device has been
reset?
the registry entry would have to be on most CE devices (an API call would
work too).
i need something like this for generating key material for security.
the value should change after a reset, and only after a reset,

so that 2 different processes running at the same time could generate the
same key.
after a reset, the next time both processes run, they should be able to
generate identical keys again;
although that key will be different then the one they generated last time.

also, time will not work, because it could be left powered on for multiple
days.

Thanks,
casey
http://www.brains-N-brawn.com
Click to expand...
Click to expand...
 
I posted this in another group, but for the benefit of all:

HKEY_LOCAL_MACHINE/Comm/BootCount
 
Good point Paul,

i'm also using the DeviceID to generate the key too.
this will make sure the key is different between devices; but can be shared
among processes.
although the ones that do update BootCount will get a new key every boot,
and be slightly more secure.

BTW this is for a CF ProtectedMemory implementation:
http://blogs.msdn.com/shawnfa/archive/2004/05/17/133650.aspx

Thanks,
casey
http://www.brains-N-brawn.com


Paul G. Tobey said:
Casey,

Don't forget that it doesn't necessarily increment on all devices every time
(because they may not persist their registry just because the BootCount
changed).

Paul T.

Chris Tacke pointed me to HKEY_LOCAL_MACHINE/Comm/BootCount
Thanks

[not directly related to CF]

is there a system registry that changes after each time the device has been
reset?
the registry entry would have to be on most CE devices (an API call would
work too).
i need something like this for generating key material for security.
the value should change after a reset, and only after a reset,

so that 2 different processes running at the same time could generate the
same key.
after a reset, the next time both processes run, they should be able to
generate identical keys again;
although that key will be different then the one they generated last time.

also, time will not work, because it could be left powered on for multiple
days.

Thanks,
casey
http://www.brains-N-brawn.com
Click to expand...
Click to expand...
Click to expand...
 
Back
Top