Code protection for the propeller

Don M

Has anyone devised a way to protect the code from being copied from a device or product that uses the propeller? If this has been discussed before I apologize. I did search the forum for "code protection" but it did not turn up any results.

I would assume that one could just copy the eeprom data and produce a copy of the program. Am I correct? Maybe the use of a Maxim digital serial number chip (DS2401) could be incorporated?

Any discussion?

Thanks.
Don

Mike Green

This has been discussed at incredible length before. I don't have the link to the thread though. I think it came up with regards to the Prop II design. Although there are no promises, I believe the Prop II will contain a fusable link ROM (write-once) that's 32 bits (one long), sufficient to hold a key for a program in EEPROM. The bootstrap loader won't necessarily load an encrypted program, but the user could have their own loader that handles decryption. On the Prop I, there's nothing built into the chip that would do this for you. It's possible to do all kinds of things externally to make things difficult, but one can always monitor the bus traffic from external devices to the Propeller to break any protection scheme. Even with the Prop II (or protected microcontrollers), it's quite easy to remove the encapsulation and gain access to internal areas of the chip. It may be difficult and not inexpensive to get around code protection, but it's quite doable with most "protected" microcontrollers on the market.

Don M

Mike- Thanks for the reply. So maybe the more realistic approach would be grinding off ic information and encapsulating in epoxy. I understand that if there is enough at stake it is hard to hide stuff but one can make it difficult for those not willing to put a lot of effort into it. I was just curious if anyone had devised anything.

JonnyMac

If someone really wants to clone your product, they will find a means to do so. One always has to balance the possibility of that happening (will it, really?) with the unit-cost impact of attempting to thwart cloning.

Until the Prop II you might add a 1-Wire serial number (if you need temperature in your product you could use a DS1822 or similar to get a serial # and temperature) -- you'd have to program each product for the serial number, and obfuscate the SN within your code to prevent clever crackers from undoing your scheme.

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Jon McPhalen
Hollywood, CA

Post Edited (JonnyMac) : 1/25/2010 3:49:15 AM GMT

Bob Lawrence (VE1RLL)

Code protection was discussed here:

http://forums.parallax.com/showthread.php?p=709423