How to give hardware security to our software

[Xcom_Cheetah]

i m having a project in which we r deciding(its not part of original project) to provide security for our software through the hardware.. like we want that during the execution of the program, the program from time to time send a signal to the hardware device connected on com or paralled port and the device return a signal and than the main program continue execution... but the problem is that how to construct this hardware device.. wot it will need ? a processor and some sort of ROM.... and how we will program this ROM..?? is this whole setup implementable at home level and light on pockets.:)
Anyone experience who can guide to the right part..

Thanks

[dighn]

maybe a timer chip like the 555 that periodically activates your program? I dont' think it's wise to make the device really fancy because if anyone really wanted to crack the security they can easily do it from the software side.

[DeadKen]

So you want to create your own dongle, eh?

I would suggest you look at USB. There are some really easy USB chips these days, which look just like comm ports, so programming is a breeze.

[bryce777]

If they are guaranteed to be on a network, you might want to have them ring in every few days and get a vaildation code of some kind.

I don' think many users will be thrilled about what you are doing, but they will be less thrilled about installing actual hardware just to use your software.

Who are you marketing this to, and what sort of application is it?

[Xcom_Cheetah]

Yes i want to know more abt dongle.. and how can this be custom built.. i have heard intel 8015/8017 chips are easy to program and compile.. and do we need to put some ROM on it..??

[DeadKen]

Originally posted by Xcom_Cheetah
Yes i want to know more abt dongle.. and how can this be custom built.. i have heard intel 8015/8017 chips are easy to program and compile.. and do we need to put some ROM on it..??

I'm not sure of the pricepoint you are looking at, but you might look at the AT family from Atmel or PICs from MicroChip.

One nice thing about the Atmels, there is GCC available for them.

Price is around $1->$5 depending on the flavor.

I would start looking at something like http://www.avrfreaks.net for info on programming AVRS and something like http://www.ftdichip.com for USB info.