yet another simple serial protection system

[tester]

This is yet another simple protection system.
I find it interesting for other needs, but may be helpful for you.

How it works?

Array of chars (letters, common signs, case sensitive) is ued.
Each letter is assigned to random number and re-randomized array of input chars.
Thus - each letter is encoded as ##$, that is 2-digit number and single mark.

For creating matched keyfile - only first two and last two chars are used (you can extend it).
So if you have "abcdefg" username, then keygen will use a,b,f,g letters.
Chars are encoded to the formula ##$##$##$##$, that is - number-letter pairs.
Then you need to create the keyfile with username and serial number (can be automated from schematic).

And now the trick, how you can use it.

1) User is asked to enter the key.
2) If username and serial number match - keyfile is saved.
3) At the same time - indicator(s) is/are saved in some secondary options file (under the name of some unused gui setting).
4) On load - program should check the keyfile (whether the username and serial number match) AND the indicator(s) in options file.

Benefits:

Since username and serial number must match (to some degree - user does not knows to what degree) - you have the control over the data you associate with the serial number in keyfile. It's a psychology.

If you use the trick (indicator) - copying the keyfile only - will not activate the app. And your options file may be stored or hidden somewhere else than your app.

User/keyboard friendly (sometimes needed) serial number (can be entered manually).

*

As you can see - it's not complicated. It uses more of psychology than hi-tech.

John Smith
32m12x56p01!

[tester]

Attaching small fix, and - "advanced" version.

Advanced version encodes every letter. Note, that empty spaces are not allowed in this version (use _ instead).

[jjs]

Very Nice!
Thank you Tester !

[tester]

...and a small converter to keep your string without spaces and endlines.

You're welcome!

[CoreStylerz]

Is really easy to crack.

[tester]

Sure. This little piece is about psychology of protections, not complexity of them.

If someone is a thief, then they will do anything to steal it anyway.

[Father]

I think using mac address or hard disk serial (I don't know if there is any other system info in FS), could be useful to create user specific challenge code, and the key file for that code.

[tester]

Especially if you change the hardware or use multiple computers.

[CoreStylerz]

I use hdd.
But i allow more than one machine per user using a server and a php script.

[Father]

Especially if you change the hardware or use multiple computers.

Good point! but really how many computers do people use or how many times they change their hardware? I think its manageable, unless you are native instruments!