Protect the code

[jason]

I have almost finished a very complicated and time consuming project. Code protection is very important to me. But I do not feel I can trust the code protect feature in the pic. so now what ?

What do you guys think of frying an IO and having a simple code that says if this io is low then erease the pic, that sort of thing ? the IO would have to goto no where otherwise the pepole who are trying to make a clone would try to find out what it is for. Normally an IO that is tied no where goes high, becuase of the internal pullup. but if we could only fry that part then it might be able to read low.

The thing is the code would need to be descrete, otherwise these copy cats would see it easy.

[RussMartin]

The subject of code protection came up in one of the classes I attended at Microchip's 2007 Masters Conference earlier this month.

According to the information I received, if the CP bit is set: So far, no one has come up with a way to beat it short of a physically invasive method--microscopic examination of the die.

Russ

[Darrel Taylor]

It figures Microchip would say something like that.

But with devices like those linked in post #4.
I'm not sure how they can keep a straight face when they do.

They keep changing they're links, so if they don't work goto

http://www.semiresearch.com

and select "Secure MCU Readers" from the menu.
<br>

[mackrackit]

Every time someone builds a better mouse trap.
Someone else builds a better mouse.

[RussMartin]

It figures Microchip would say something like that.

But with devices like those linked in post #4.
I'm not sure how they can keep a straight face when they do.

Well, I'm not going to assume that the Microchip people are in the same class as sleazy used car salesmen. As I wrote, the statement was qualified with "so far". However, I've forwarded the link with a question to my FAE, and I'll report back his reply when I get it.

They keep changing they're links, so if they don't work goto

http://www.semiresearch.com

and select "Secure MCU Readers" from the menu.
<br>

I notice that the list of target devices for both readers is still very, very short. (You have to wonder why it takes one device to do the '877 and the other to do the '877A.)

I've E-mailed them for price information, availability, warranty/guarantee information, and asked if they will provide free upgrades as other PICs become supported. I note that their sales office is in China and their lab is in Lithuania.

-----------------

My understanding is that IP (intellectual property) theft right now is worst (and rampant) in China and in India: In China because IP theft is almost a way of life in engineering and technology, and in India (Jerson, correct me if this is wrong) because their laws and court system have not kept pace with the development of technology.

[NF9Ω]

http://www.mcucrack.com/ and http://www.waferstar.com/en/index.shtml doing this job for all microcontrollers.

I know some devices extract code from AT51/52 micro.
Just insert microcontroller, Press start button, and all code save in 24c64 in 4 min.
I always protect microcontroller to apply 24v 10ma power source only once to eny pin of PORT0 ( that are not used )with respect ground , No one extract code after this.

[RussMartin]

http://www.mcucrack.com/ and http://www.waferstar.com/en/index.shtml doing this job for all microcontrollers.

Zhonghai (the first link) uses what they call "intruded crack"--that involves going in and looking at the physical die. Not much protection against that. Wafer (the second link) doesn't seem to show anything on cracking. What did I miss on that site?

I always protect microcontroller to apply 24v 10ma power source only once to eny pin of PORT0 ( that are not used )with respect ground , No one extract code after this.

This sounds interesting. Can you describe why and how this works to protect code? Does this prevent just reading the code? What about the invasive ("intruded crack") approach--can't someone still recover the code by microscopic examination of the die?

[NF9Ω]

If you write to weferstar for code recovery they will quote rates.

No one can escape from microscopic examination of the die.

[Jerson]

The subject of code protection came up in one of the classes I attended at Microchip's 2007 Masters Conference earlier this month.

According to the information I received, if the CP bit is set: So far, no one has come up with a way to beat it short of a physically invasive method--microscopic examination of the die.

Russ

I have heard these quotes before. All I know of cracking devices is, that it's as simple as burgling a house. When you leave home, you put the biggest padlock you have on your door and bolt it down. When a burglar strikes, he reverses the procedure. The last time I read up on this topic, I learnt about using devices out of spec (power/timing) to beat various protection schemes. The power glitch is one very interesting technique and is sucessfully used by 8051 hackers. A related phenomenon is when you have the flash being corrupted by mere power on/off cycles. BTW : the Rst pin in the 8051 family usually is the VPP pin. Doesn't that say enough? I am almost sure that most flash micros are prone to this type of failure.