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  1. #1
    Join Date
    May 2010
    Posts
    8

    Unanswered: Licence and copyright my database

    I have been working on a database I would like to offer on a trial basis to companies is there software to licence it and does anyone have tips on copyright.

  2. #2
    Join Date
    Dec 2004
    Location
    Madison, WI
    Posts
    3,926
    There are a few different ways to do this. What I've done sometimes is write code (embedded with the startup code) which looks at a value in a table to identify a serial type number and verify authentication (along with any copyright coding). The easiest way though is to only supply an mde file with limited features.

    You can look at this post by izyrider regarding serial #s: http://www.dbforums.com/6225215-post9.html

    If you want to offer a 'trial' type application, I'd again, recommend supplying them with the mde file only with the option to purchase the product and get the source code (and have a disclaimer once the source code (mdb) file is purchased.) With only the mde file, they cannot see/modify any coding.

    I also have a disclaimer that if the source code is modified (in which I may use 3rd party software to compare any coding changes), I charge accordingly to fix/modify.

    Note though that if a company does purchase the application, you should supply the source (mdb) file (that's my personal belief) or make it somehow accessible (in case you're no longer in business). Otherwise they may try to contact you again in the far future (for example - they upsize MSAccess to a newer version and your application no longer works.) I cannot elaborate about the legality of supplying the mdb source code when a company purchases the application since I've always supplied this but I'm guessing that you could find yourself digging up that application years later if you don't.

    Here's a few tips I found: http://discuss.techinterview.org/def...iz.5.440742.16
    Last edited by pkstormy; 07-23-10 at 14:02.
    Expert Database Programming
    MSAccess since 1.0, SQL Server since 6.5, Visual Basic (5.0, 6.0)

  3. #3
    Join Date
    May 2010
    Posts
    8

    Code novice but I was wondering...

    Thanks for your reply although its over my head. Sorry it took so long to reply but became a dad again so its been hectic. Would it be possible to put code somewhere that would not let the database open if Todays date was greater than a date I could manually put in the code then give it out as a mde file. I could then give people it as a demo that would not work after a date I specify. Would this be secure?

  4. #4
    Join Date
    Dec 2002
    Location
    Préverenges, Switzerland
    Posts
    3,740
    this old thread illustrates one way limit the application to a specific PC (machine ID).

    rather than machineID you could limit to a maximum Now() on the user's machine (keep in mind the user can always fake the PC clock). you will still need a secret and Hash() see the old thread for discussion of secrets and Hash()

    locking to a maximum Now() might progress as follows.

    save in some TableLicence:
    DemoExpiry, Datetime '-- the last allowed Now() for startup
    DemoKey, String '-- Hash(DemoExpiry & someSecret)

    your demo-validity check is simply:
    Code:
    if (Now() > DemoExpiry) and (Hash(DemoExpiry & someSecret) = DemoKey) then
    'OK
    else
    'not OK
    endif
    is it secure?

    yes for normal users, but whatever copy-protection scheme you choose, you have no chance at all against someone with motivation, skills, tools, and time. major software houses throw millions of dollars at copy-protection and it doesn't do them any good.

    izy
    Last edited by izyrider; 09-07-10 at 14:47.
    currently using SS 2008R2

  5. #5
    Join Date
    May 2010
    Posts
    8

    Drowning in code speak

    Hi izy
    I'm only a access novice and the most I've done with code is copy and paste when people such as youself have kindly helped me out with a specific problem. My db has taken me 3 years of amateur struggle, problem fixes and work arounds so I don't want to give it away for free. Is it possible to simply put code in my startup form to stop it opening as you suggest but without the hash and secrets etc?

    I could have this in the mde front end of a split db and if they want to purchase it I can swap the front end for one with no startup form expiry code. I take your point that they could simply change the date on the PC and it will work again but my reports use Now() to run so the reporting would not be accurate. All I'm looking for is normal user copy safe, and some way of being rewarded for my work. Your help is very much appreciated.

    Mushashi

  6. #6
    Join Date
    Sep 2007
    Location
    Global Village
    Posts
    185
    izy is quit right about securing your application, I think there is no lock that nobody can open it.
    There is a way I use it and it is a little useful that I put a code in my demo dbs to check and do not let user to add more than say 50 records.
    Also for purchased dbs I put a code to check the serial number of one of the computer hardware like Hard disk and if it is not the given one then it quit the program so they can not copy the program on other computers without your authorization, this is good for those who sell thier db for example shops and supermarkets but not useful for companies with several users.
    <<Never Walk on the Traveled Path, Because it only Leads you to where the Others have been.>>
    Graham Bell

  7. #7
    Join Date
    Dec 2002
    Location
    Préverenges, Switzerland
    Posts
    3,740
    Mushashi,

    .. the link i provided above to a very long discussion about a simplified 'licencing' scheme provides all the information (and sourcecode) you could ever need about SHA1 hashing and naïvely embedding secrets in an application (it's user-proof, not hacker-proof).

    i'll happily build you a licence generator and 'protect' your .MDE for free, but:
    a: no chance in the next two weeks - i'm well over 100% busy
    b: since i have now given up with Access (because of Access-2007!) i only have one Access support machine left - it is Access-2003: any code we swap must be Access-2003
    c: you must provide me with the front-end .MDB in Access-2003 format (so you give me the power to broadcast your code worldwide)
    d: i will provide you with a .MDE of your front-end that will accept time-limited licence information from a .TXT file.
    e: you and i will be married - you will not be able to change your 'protected' front-end code without my help (it will not be free second time!).
    f. i will have the sourcecode for licence generation for your application: i can broadcast that worlwide.
    if you want to play this game, PM me and i'll send you a disposable mail address you can use to send me the .MDB

    or

    go thru the code examples in the old thread above and do it yourself - it really is not difficult to block normal users from making unauthorised copies.

    izy
    currently using SS 2008R2

  8. #8
    Join Date
    May 2010
    Posts
    8
    Izy
    Message received and understood.
    Mushashi

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