Zeroization implementation

[Kepco]

Hi Guys,
What will be the best way to provide Zeroization option for a system without using an external (Covered) switch? Zeroization pin when grounded clears all the software on the system. Some systems have implementation that takes external 12V pulse with isolated GND to trigger the internal system Zeroization pin grounding. But this approach require an external 12V source. The requirement is to have this implementation exercised remotely vs by a local switch. Any thought on this will be appreciated.
Thx

 

[VEBill]

Perhaps there could be a local relay that applies the local zeroization ground upon application of coil power from a remote location. No local power required.

I'm making all sorts of assumptions about how the zeroization works in this equipment; I presume it's based on volatile memory?

 

[Kepco]

This could be an option. The Zeroization pin on a system board connector when detected by the software as grounded, all the software stored in the flash memory of the system is wiped off.
Thx for the input.

 

[VEBill]

Hopefully the equipment doesn't have an OS that could cause an error as follows:

Zeroization detected - Wiping Flash!
1% ...
2% ...
ERROR - File Not Found
Operation Aborted

That would be bad.

Also, many larger flash memories have hidden spare sectors used to prolong the lifespan. These hidden sectors cannot be accessed by the OS in the usual manner, and thus may allow some data leakage.

Also have to think about power outages, if the application demands it.

 

[Kepco]

Very good points. Unfortunately this system has an embedded OS. The system power source should have battery back up in case power is out to implement this feature.

Thanks.

 

[MacGyverS2000]

If this is a Flash drive or one form or another, I hope you're keeping track of the bad sector table... if you simply wipe the entire device, you're going to get bad reads real soon.

Dan - Owner

http://www.Hi-TecDesigns.com

 

[IRstuff]

Generally, a zeroize needs to be performed in a specified time; I've seen requirements for 3 seconds. That's not a time frame that typical flash memories can clear themselves. Have you considered encryption?

TTFN
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[VEBill]

The drive should have a 'Secure Erase' command.

http://digital-forensics.sans.org/blog/2011/01/25/digital-forensics-erasing-drives-quick-easy

Depending on the requirements, it might be an approach.

@Kepco - are you simply interfacing to an existing system, or are you involved in the design of that system.