Time Restricted Software

[Gadget]

It probably is as simple as that but what happens if he only downloads the program on the 31-12-2003 he only gets one day to use the software.

I was thinking of something that possibly uses the registry and stores the installation date etc (encrypted) and then stops working after a specified time period.

Oh well I('ll make my own little component. Shouldn't be too hard

One of the problems with registry checks is they are prone to 'Installation Capture' type attacks. ie. Install Shield, captures registry settings when the application installs and first runs. There are a couple of clever solutions to this problem, one is to write something that runs say 3 days after the install date. This then means that the install capture won't register the modificiation, and ensure that on uninstall that the registry entry is not removed. You can also get clever by using file attrib flags for various non changing system files, say for example using the Archive flag. Another nice unique feature that I have employed is using a random (say 1 in 50) net check. If they are connected to the internet, the application checks for a newer version, at the same time it checks the server date and time, realises its a trial version and disables the application.

[Traveler]

If they are connected to the internet, the application checks for a newer version, at the same time it checks the server date and time, realises its a trial version and disables the application.

Wouldn't ZoneAlarm (or any other firewall) give me a warning and the option whether the program is allowed to proceed with the connection? I could choose not to connect.

[cairnswm]

I've been looking at doing shareware for a while now. I have also been reading up quite a lot about it over the last few months. It is quite clear that using any form of time delay/expiry software is not a good plan as they get cracked very fast (on the Game Vision forums the one person said two days...).

I will use a demo vs registered copy approach to my shareware.

[Gadget]

If they are connected to the internet, the application checks for a newer version, at the same time it checks the server date and time, realises its a trial version and disables the application.

Wouldn't ZoneAlarm (or any other firewall) give me a warning and the option whether the program is allowed to proceed with the connection? I could choose not to connect.

That's true, but one thing I have been thinking about is using other applications to bypass the firewall.

eg. Shell IEXPLORE.EXE, send a url to it passing the reg number as a query string, then read the text returned using the GETTEXT message or similar?