How To Make Time Trail Demo

[Proosy]

Can anyone please tell me the best way to make a time trialed edition of an application in visual basic 5 ?

ie do i just create a file somewhere hidden on the system, which contains the date of the first time the application was run, and simply check this each time program is run.

Or is there a better way using the registry or something?

Any idears would be great thanks.

[kinjalgp]

Hi!

Visit http://www.activelock.com where you'll find a free ActiveX control which allows us to make timetrial demos as well as password protected sharewares. However I'm not going to use it in any of my software demos because I got the secret of where it stores data and if someone else is also aware of this then I am goneeeeeeeeeeeeeeeeee................

So I just advice you not use it. Simply learn some encryption technique and store the data in the registry. I bet you no one will be able to retrive the password from the registry accept you until they know your encryption technique.. encryption is giving a password and exoring it with any of your another password and store the result in the registry. And when someone enters the key or password obtained from you your program should get the encrypted password from the registry and compare with the entered pass. if it is true then it's done or RETRY!

You will also find encryption techniques in some few month old posts. Try searching it.

Good luck!

Kinjal

[Proosy]

Thank You Very Much !

[kedaman]

Ok i have some other good ways:
1. Put the time appended to the exe while using a different encryption every time
2. Put it in a file, preferably your own, same way encrypted
3. Put it in many places in registry and xor them against other critical registry keys. In this way you can prevent someone from copying the app after it have been installed, to use it in another computer

Also, don't use timetrial method, it's too easy to crack, just turn back date before running it. Instead put it to count times excecuted.

[gabriel.hege]

Hi!
I read the previous replies and they are all gerat ideas, except that those programs are really easy to crack. With a disassembler like "win32dasm" you can disassemble VB programs and get around the password protection easily without great knowledge of assembler.

Usually you just have to patch a couple offsets in the exe-file and you can "register" the program with any password except the right one. This is done by changing the instruction in the position of the comparison between the right and the wrong password from the command 'je'(jump if equal) to 'jne'(jump if NOT equal).

My solution to the problem (which I don't have because my programs are freeware :-) is to use a tool that encrypts the exe so it can't be disassembled so easily. I read about a tool available at http://www.bit-arts.com . Their software is pretty expensive but I am sure there are similar freeware programs out there, too.

I hope now I said enough...

CU,
K-os