Leaded QFP is easy to get access to the chip. Cut the leads off, you pop the chip easy. In addition, nowadays, you can get some precision de-lid instrument come down to the near surface of chip level. It is hard to protect it as after thoughts. If you want secure at concept level, it is a different story. You can pot something in stuff similar to cement if you packaged well and make sure it fracture when it experience excessive stress (either by removing or bias. If not bias properly, it would fry for example. But that still may not prevent someone to get few of them to do an reverse eng. The trick would be, make sure it is not widely in circulation for example, or it become cost prohibitive or time prohibitive). It is all in the design. If your design is done, it is difficult to protect it. Too late. If someone really want to get it, there is nothing to stop him with a leaded package. My 2 cents.
--------------------------
Sent using BlackBerry
----- Original Message -----
From: Bev Christian [mailto:[log in to unmask]]
Sent: Friday, April 26, 2013 07:36 PM
To: [log in to unmask] <[log in to unmask]>
Subject: Re: [TN] tamper proofing electronic assembly
I agree with Dave - from personal experience of having to do it for the
security types in a company of my employment.
The ONLY way I know of to really make it tamper proof is to build it in a
metal box such that if it is opened the circuits inside are fried. That is
what Nortel (now deceased) did for desk phones it built for the UK military.
Bev
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of David D. Hillman
Sent: Thursday, April 25, 2013 9:38 AM
To: [log in to unmask]
Subject: Re: [TN] tamper proofing electronic assembly
Hi Eric - have you investigated the use of an epoxy based non-reworkable
underfill material? It has been my experience that trying to remove this
family of materials results in ginormous damage. But - you will need to
test to make sure you don't cause solder joint issues for the LQFP
component with its use. Also note that there is no such thing as a "make
it impossible to remove without damaging it" as given enough time and
techniques, any material can be removed carefully enough to not cause
damage as reverse engineering is a science, not an art.
Dave Hillman
Rockwell Collins
[log in to unmask]
From: Eric Laroche <[log in to unmask]>
To: <[log in to unmask]>
Date: 04/25/2013 07:48 AM
Subject: [TN] tamper proofing electronic assembly
Sent by: TechNet <[log in to unmask]>
Good morning,
One of our customer has requested, for security purposes, that we
assemble their board in such a way to make the removal of the
microprocessor impossible without damaging it. The component is a 64
pin LQFP. The design is already completed and this requirement came
afterwards.
Our approach so far has been to add a material over the part and on the
leads prior to conformal coating. All the materials we have used to
this point have been peeled away when heating the component.
Is this something that some of you have been requested before? How have
you managed to do this?
thanks for your feedback,
Eric
______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask]
______________________________________________________________________
______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask]
______________________________________________________________________
______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask]
______________________________________________________________________
---------------------------------------------------------------------
This transmission (including any attachments) may contain confidential information, privileged material (including material protected by the solicitor-client or other applicable privileges), or constitute non-public information. Any use of this information by anyone other than the intended recipient is prohibited. If you have received this transmission in error, please immediately reply to the sender and delete this information from your system. Use, dissemination, distribution, or reproduction of this transmission by unintended recipients is not authorized and may be unlawful.
______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask]
______________________________________________________________________
|
