[Fwd: Re: Firmware Protection]

Started by Jeff Brower August 21, 2003

What Microsoft did with X-box is interesting. They faced a similar problem --
EEPROM on the processor itself. So they used a Flash ROM device with a small
bootloader (processor) to handle decryption during boot. They did some things
JTAG also, like tying ~TRST to an internal gnd layer underneath a BGA package.

Below are some links for additional information on the Xbox approach. It seems
author has actually hacked the Xbox and has some useful information for those
to design hardware to prevent hacking. When you realize this is a grad student
PhD at MIT, so ultra grad student) who has gone so far to get a hold of
precision soldering equipment (e.g. replace the FLASH EEPROM with a socket),
decapsulated the Celeron, Nvidia GPU and southbridge, and is maintaining a
web pages with updates based on communication with several others working on
areas, then you realize how effective reverse engineering can be if done by a
talented person with energy and time.



Jeff Brower
system engineer
Signalogic -------- Original Message --------
Subject: Re: [c54x] Firmware Protection
Date: Thu, 21 Aug 2003 15:52:50 -0400
From: "Andrew Xiang" <>
Reply-To: "Andrew Xiang" <>
Organization: Andrew Xiang
To: <>, "Rodrigo Rivas" <>

You cannot prevent it. But you can make it harder: 1. write messy code and
messy hardware.2. put a EEPROM with a fixed value and different on each board.
a portion of your program using the code.3. make the product dirt cheap so there
no incentive to copy. that is all I can think of. -Andrew

----- Original Message -----
From: Rodrigo Rivas
Sent: Thursday, August 21, 2003 12:56 PM
Subject: [c54x] Firmware Protection
Hi , How do you protect the firmware in your custom boards ?In our custom
board, there is an external Flash in which reside the firmware. The
firmware can fit in the on-chip RAM of the C5416, then after bootloading,
the C5416 run from on-chip RAM. Then the problem is how to protect the
firmware that reside in the external Flash against copies ? any help is
welcomeThanks in advance Rodrigo Rivas