On Fri, May 6, 2011 at 12:31 PM, Paul McNett <[email protected]> wrote: > On 5/6/11 4:41 AM, Jerry Foote wrote: >> I would appreciate opinions as to the best copy protection scheme for a >> general distribution program. > > I allow my software and application data to be freely copied (make it easy > for paid > customers to do what they want). But there's a license file in the appdata > directory > that: > > 1) must be present for the application to start (if not, a screen prompts for > the > license, directing the user to the web page to purchase a key) > > 2) the applications checks the status of upon each app start, but if the > computer is > offline it allows a max. of 20 days to pass before saying "go online so I can > check > the validity of your license". > > 3) uses information coded in the license file to generate the company name, > city, > state, and phone number fields. This information, from the license, is what > gets > shown on screens, in reports, etc. So you can't just copy another user's > license > unless you want to represent yourself as that user. You also can't change the > values > in the (plain-text) license file because the software looks at the hash and > compares > it with the encrypted hash in the same plain text file. Change one character > in the > license file, and it is no longer valid. > > We control the validity of each license on our servers, and can turn them off > and on > at will. In our case this software is free to customers above a certain > purchase > volume that are in good standing. If they are late on a payment we've found > that > invalidating their license results in a check going into the mail > immediately. I > don't think anyone's yet figured out that they could last 20 days on a bad > license by > just unplugging the internet when the app starts. -------------------
I like the idea. Back in the dial up days I used a local table that kept the encrypted code as well as Customer name , address,..... If they just changed the company name I would put demo flag to true and allow 30 days to run. There was warning messages at start up letting them know and instructions to contact me as well. I use to sell to Used Car dealers and found that a snap-on tool guy was given a PC for payment of a bill and my app was on it. He copied that and sold it I was told all over NW TN, an area I never concentrated on in sales. He had an earlier version of my app that that didn't have the protection built in. -- Stephen Russell Unified Health Services 60 Germantown Court Suite 220 Cordova, TN 38018 Telephone: 888.510.2667 901.246-0159 cell _______________________________________________ Post Messages to: [email protected] Subscription Maintenance: http://leafe.com/mailman/listinfo/profox OT-free version of this list: http://leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/[email protected] ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
