Post by thread:Embedded System Protection

Howdy All, A friend of mine recently asked for my help in protecting an embedded system of his from unauthorized duplication. He has designed a 16 bit embedded system that uses an external EEROM for program storage. The PCB is simple and easily copied, so he is worried that pirates will purchase one of his units, make copies of the EEROM and duplicate his hardware, thus selling clones of his design. He has contacted me to help produce a "code protection" microcontroller that would function like a "dongle". Without this code protected PIC chip installed on the board, the units would not function. 1. How secure are the code protected PIC chips? 2. Does any one have experience doing this? 3. Should the PIC hold valuable "key parts" of his code? I think this is a great use for a PIC chip and great opportunity for PIC programmers to make some money providing unique system protection chips. Please let me know your thoughts. ---- Steve spam_OUTstevemTakeThisOuTtanisys.com

>A friend of mine recently asked for my help in protecting an embedded >system of his from unauthorized duplication. He has designed a 16 bit >embedded system that uses an external EEROM for program storage. The PCB Maybe he can use a GAL do to his address decoding, and read-protect the GAL. That method has been used by more than one vendor that I am aware of... Jeff Otterson ------------- .....ottersonKILLspam@spam@mindspring.com Maker and user of tools PGP key available at http://www.mindspring.com/~otterson/pgp.htm

Jeff Otterson/N1KDO <ottersonKILLspamMINDSPRING.COM> wrote: > Maybe he can use a GAL do to his address decoding, and read-protect the GAL. > That method has been used by more than one vendor that I am aware of... Protected GALs can be easy copied without reading the devices' fuse map. It's especially easy in case of an address decoder, where no latches are used and there is one-to-one assignment between input and output values. I've done this several times (for replacing defective parts, not for stealing somebody's code !). I've read the truth table of the chip with an EPROM programmer, then reduced it and converted to a CUPL source file using a program written in C. - Piotr Piotr Piatek .....pisielekKILLspam.....inet.com.pl

> Jeff Otterson/N1KDO <EraseMEottersonspam_OUTTakeThisOuTMINDSPRING.COM> wrote: > > Maybe he can use a GAL do to his address decoding, and read-protect the > GAL. > > That method has been used by more than one vendor that I am aware of... > > Protected GALs can be easy copied without reading the devices' fuse > map. It's especially easy in case of an address decoder, where no latches > are used and there is one-to-one assignment between input and output > values. Reading out a protected GAL in which there are no latches is trivial; on GALs with latches things may be harder but if no latches are buried it's still easy. Reading out a GAL with buried latches may be a little bit difficult, but since at most 9 latches may be buried in a 22V10 that does anything useful I would not expect this to be any more than 512 times as hard as reading one with no buried latches (which I would expect to be fully automatic).