Thanks for all the comments about this..my client has decided to continue t= o do upgrades by having them send in the unit for updates, at his expense i= n order to try and keep the code semi-secure. --- On Wed, 5/20/09, Isaac Marino Bavaresco w= rote: > From: Isaac Marino Bavaresco > Subject: Re: [Bulk] Re: [PIC] protected code > To: "Microcontroller discussion list - Public." > Date: Wednesday, May 20, 2009, 1:25 PM > Richard Prosser escreveu: > > If the client is determined that his clients have web > access to the > > hex file, why not get him to setup a password secured > web page? > > > > RP > > > > 2009/5/21 Herbert Graf : > >=A0=A0=A0 > >> On Wed, 2009-05-20 at 07:09 -0700, alan smith > wrote: > >>=A0 =A0=A0=A0 > >>> Setting the code protect config bits is > supposed to give you a layer of protection, when at least > trying to read back from the actual device.=A0 I wont get > into the discussion about how that can be gotten around. > >>> > >>> My question is...when you generate a hex file > with these set, can it be dissassembled..ie..is the code > protect only valid for reading back from the device. > >>> > >>> The basis for the question is a client wants > to put code updates for a product on his website, so anyone > can download but doesnt want someone to easily able to > reverse engineer it.=A0 I wasnt sure if this protects the > hex file. > >>>=A0 =A0 =A0=A0=A0 > >> The code protect bit is just a setting in the > PIC's config space, aside > >> from that bit being flipped in the hex file there > is no difference in > >> the hex file. > >>=A0 =A0=A0=A0 > = > Most probably one must prevent everybody, including the > customers, from > being able to clone the product. > = > Most circuits are usually simple to clone. If somebody has > access to the > firmware, then he can build many boards by himself and stop > buying from you. > = > The only safe approach is to use a cryptographic > boot-loader. > = > Regards, > = > Isaac > = > __________________________________________________ > Fa=E7a liga=E7=F5es para outros computadores com o novo Yahoo! > Messenger = > http://br.beta.messenger.yahoo.com/ = > = > -- = > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > = = -- = http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist