Protecting/licensing/distributing my Access 2K prog. 2

[vinil]

Hi,

I have developed a software system based on Access 2000 and I wish to protect the code and distribute license copies or 30 days demo copies to the prospective clients. I have never done this before.

Are there any security pitfalls with .MDE files that I should be aware about. Is there any set procedure to create the full version demo copy that only woks for say 30 days or do I just store the date of installation and compare it with system clock each time.

Are there any other ways I can use to protect my application better.

 

[SQLBI]

Vinil,

If you've protected the database with the Security Wizard the process i use is quite simple.

In a separate table, i have 2 comlumns, Locked and Date.

I set the locked record to 1 and the date n days into the future.

When the startupform of the db opens, it checks if the locked cell is 1 or 0, if its 1 it compares the system date to the date record and if it's later it locks the db and quits access.

then when the client pays, i send them a code/password to enter into an admin form, which updates the Locked 1 to a 0.

Its probably not the best way but it works for me.

Hope this helps.

Leigh Moore
LJM Analysis Ltd

http://www.ljm-analysis.co.uk

 

[Parax]

you could also increment a value in the table to give say 30 runs before it locks. you may also want to have a trigger field so that once the date has been passed it trips the trigger to prevent the user adjusting thier system clock. (I presume you are encrypting and converting your database to an MDE file. otherwise it is simple to reverse these changes.)

The other issue is how to stop the user from copying the database when you send it to them or once it expires to stop them from re saving it from the email you send them. in order to prevent this you may need to write a registry key that also holds a lock value.

 

[Parax]

PS
an mde file does not protect the data in the tables only your code! you will want to create a robust front end with access keys disabled and make sure there are no backdoors to get to the database window in order to protect your lockout table (and encryt your database!).