Best way to evaluate a program

[djpaul]

Hello!
I just finished a program to collect photo's and where you can search for particalur photo's.
But some people want to buy this program, so i want to lock it with a code.
So that they won't make a copy of it and have there own code.

What is the best way to lock a program for example 14 days and then lock some settings or features.

Regards, Paul

[tlhintoq]

The absolute strongest method is hardware.
If the program is always in demo mode unless the needed hardware security dongle is attached to the PC then it doesn't matter if they copy the software. This is just one maker of such devices. If you google for "security dongle", "software dongle" and such you should get several other makers.
Hardware HASP page
Personally I like Aladdin's HASPS because they have clocks and memory you can read/write. So you can offer various options and enable them by setting a bit in the memory of the dongle.

I believe they also make a purely software component that you can add to your software. Basically a wrapper that allows you to set a demo period, after which the software dies etc.

Plan C: You could have your software check a server over the internet for code validation and unlocking.

[djpaul]

Okay, plan c is what i was thinking of.
But what is in that the best way to count down the days?
If somebody change the system time, it works forever, altough the time of your machine will be far behind after a while....

thanks!

[tlhintoq]

Okay, plan c is what i was thinking of.
But what is in that the best way to count down the days?
If somebody change the system time, it works forever, altough the time of your machine will be far behind after a while....

thanks!

That is one of the oldest tricks in the book, playing with system time at the point of installation versus now. Just means you have to be smarter than your average bear, boo-boo.

How you choose to do it is what sets you apart from the next guy. Be creative and imaginative. Maybe instead of comparing date today to date of activation you do something different. Maybe the software *has* to check on-line for the date, at least while in demo mode. If it can't see the net for time then it doesn't run. Now you don't care about the system clock. Or maybe you don't limit it to the number of days. Maybe you track the number of running hours. Demo mode will work for a cumulative total of 48 hours. That could be two straight days or 1 hour a day for 48 days. That's up to the evaluator. So now you hide away a number in the registry that is coded using the crypto system so the user can't change it.

Just a couple ideas to spark some of your own.