Prevent copying application

[philcon]

Hi all,

I've written an application which may (or may not) have some commercial value.

My concern at the moment is a way of preventing unauthorised copies of the front end being made at potential customer sites.

I was thinking that if I put a field in a backend admin table which increments as users open or close the front end then I could hardcode a user limit into the application, thus the front end would close if that limit was reached.

An issue with this approach is that if the customer site wished to increase the user base, I would have to visit the site or send a new front end which would have to be setup for each user (not huge hardship).

Another issue is that non-standard front end exits would bypass the increment code causing all kinds of problems.

I was just wondering what anyone elses thoughts were regarding differing approaches to this issue.

Many thanks in advance


Phil.

 

[philcon]

No replies so thought I would try again,


Philcon

 

[smitan]

This problem can't be solved in a standard way, as I see it. Just because Access is sometimes closed via 'illegal' solutions, your counter will have a wrong value.
You might have a table, holding the usernames of all the users with a logon and logoff time.
As no users will work for more than 12 hours (or 24) you might, at every logon (no matter who is logging on), check the table for "logofftime>logontime and the logontime > 12" (or 24) hours. This will be the case for hanging users.

Like to hear your reaction.
Have a nice summer,
Hans

 

[philcon]

Hi Hans and thanks for replying.

I'm not exactly sure I understand your suggestion.

Given this scenario

Day 1
User 1 logs in at 0900 and logs out at 1700
User 2 logs in at 0900 and logs out at 1700

Day 2
User 1 logs in at 0900 and logs out at 1700
User 2 logs in at 0900 and logs out at 1700
Duplicate User 1 logs in at 0900 and out at 1700

What is the process which would prevent Duplicate User1 from logging in other than booting him/her if the user is already logged on (would again cause problems with illegal exits)

Thanks again for replying

Phil

 

[smitan]

Hi, as I said, the solution is absolutely not 100%. It only helps.
You have to set up windows so one user can only logon ones. That means Windows solves part of the problem.
Now user 1 logs in at 0900 and closes Access via the task manager and goes home. Next day he will log in and you allow that.
At ANY logon you count for the number that is using the app.
A user is logged on when the logofftime is less then the logontime. A user is logged out when the logintime is less then the logofftime OR when the logintime is more then 12 (arbitrary) hours ago.

It might happen that the number of logins is less then the number allowed and a message is shown anyway, but with remore access to the server you can easily check this.

As I said this is not a super watertight solution, but maybe my suggestion gives you an idea.

Maybe others have other suggestions or thoughts about this one?
Greetings
Hans