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indirect copy protection of Excel files
Hi,
I have to copy protect my engineering expert system somehow. I consists of one folder with 5 huge Excel files within. Those are al interrelated workbooks of around 20 MB in total. I am not talking abou either huge data base or so much data to process. I am talking abou heavy and complex algorithms, options, combinations, an optimizations...and graphics. I am not much worried even if one want to possess the formulas. Anyway, formulas are too complicated for a average user, and there are too many of them - literally severa thousands of formulas (most of cells have 7 IFs and in average 25 symbols). I am worrying about the end-user intention to copy entir folder for a purpose of giving to someone else or making some no insignificant money on it. The folder is encrypted, but the authorize user with an open access to the application/files (with exemption t the MS passwords, which is no protection at all) could do what he want to do. So is there ANY protection from copying the files at the first place o is there any way around for instance allowing the files to be copied but to become useless in a process because of some newly acquire dis-functionality? Could anyone come up with a functional code (the SOLUTION in my case that will ‘import’ actual computer ID (serial number or something) into Excel, check if it is the same one as the one written in the macr and IF NOT disable all workbooks opening functions and/or quit Exce application – i.e. close Excel altogether? The idea behind is that m XL files could run only on one computer – sort of soft-key. If file are copied and user wants to run it on another computer to make hi feel sorry. Many thanks in advance. Daniel Could anyone come up with a functional code (the SOLUTION in my case that will ‘import’ actual computer ID (serial number or something) into Excel, check if it is the same one as the one written in the macr and IF NOT disable all workbooks opening functions and/or quit Exce application – i.e. close Excel altogether? The idea behind is that m XL files could run only on one computer – sort of soft-key. If file are copied and user wants to run it on another computer to make hi feel sorry. -- Message posted from http://www.ExcelForum.com |
#2
Posted to microsoft.public.excel.programming
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indirect copy protection of Excel files
Since all a user needs to do is set macro protection to high to prevent all
code from running or spend a few dollars on a vb password cracker, there is not a lot you can do. Bob Flanagan Macro Systems Delaware, U.S. 302-234-9857 http://www.add-ins.com Productivity add-ins and downloadable books on VB macros for Excel "ysaneo " wrote in message ... Hi, I have to copy protect my engineering expert system somehow. It consists of one folder with 5 huge Excel files within. Those are all interrelated workbooks of around 20 MB in total. I am not talking about either huge data base or so much data to process. I am talking about heavy and complex algorithms, options, combinations, and optimizations...and graphics. I am not much worried even if one wants to possess the formulas. Anyway, formulas are too complicated for an average user, and there are too many of them - literally several thousands of formulas (most of cells have 7 IFs and in average 250 symbols). I am worrying about the end-user intention to copy entire folder for a purpose of giving to someone else or making some not insignificant money on it. The folder is encrypted, but the authorized user with an open access to the application/files (with exemption to the MS passwords, which is no protection at all) could do what he wants to do. So is there ANY protection from copying the files at the first place or is there any way around for instance allowing the files to be copied, but to become useless in a process because of some newly acquired dis-functionality? Could anyone come up with a functional code (the SOLUTION in my case) that will 'import' actual computer ID (serial number or something) into Excel, check if it is the same one as the one written in the macro and IF NOT disable all workbooks opening functions and/or quit Excel application - i.e. close Excel altogether? The idea behind is that my XL files could run only on one computer - sort of soft-key. If files are copied and user wants to run it on another computer to make him feel sorry. Many thanks in advance. Daniel Could anyone come up with a functional code (the SOLUTION in my case) that will 'import' actual computer ID (serial number or something) into Excel, check if it is the same one as the one written in the macro and IF NOT disable all workbooks opening functions and/or quit Excel application - i.e. close Excel altogether? The idea behind is that my XL files could run only on one computer - sort of soft-key. If files are copied and user wants to run it on another computer to make him feel sorry. --- Message posted from http://www.ExcelForum.com/ |
#3
Posted to microsoft.public.excel.programming
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indirect copy protection of Excel files
XL just doesn't have this capability. If the user can open the file,
they can generally gain access to everything in it, including hidden sheets, protected code, etc. It may be technically feasible if you have access to their machine (to get some identifying number), and if you compile all your workbooks into COM add-ins. Otherwise, you can throw up roadblocks, but they won't keep someone who is motivated, with even moderate abilities (i.e., they can find this newsgroup), from bypassing them. Having an installer that installs a hidden file or registry key upon which the app is dependent is also a possibility - it won't prevent someone from giving away your installer, but joe user wouldn't be able to simply copy the folder. As for your proposed protection scheme, though, I certainly wouldn't buy *anything* that I needed for my business that licensed a single machine - what if the machine fails and I need to use an alternate? Or what if I want to upgrade my machine - I'd have to get permission from you? No way! Some of my Windows clients put up with that BS from Microsoft (lord knows why), but not an independent contractor. I'm also troubled by your desire to make your client "feel sorry". If by "feel sorry" you mean to put up a message saying "This may be an illegal copy, you should feel very very bad", while I suppose that's something I could live with, seems unprofessional. But if by "feel sorry" you mean to damage anything I have on any of my machines, if that happened, I'd sue you for everything you've got. You have a right to compensation for your work - you don't have a right to damage *anything* of mine, even if I steal from you. Far better to get to know your clients and establish a relationship whereby they're willing to pay a reasonable price for additional desks, and for continuing support. Make it clear that this is a licensed product: put in passwords that are specific to your client, and make sure all your dialogs list both the client and you. Compile it if it doesn't need to either be cross-platform or to run on XL97. That won't prevent piracy, but if you charge a reasonable price and provide great service, ethical clients will respect your license. In article , ysaneo wrote: Could anyone come up with a functional code (the SOLUTION in my case) that will ‘import’ actual computer ID (serial number or something) into Excel, check if it is the same one as the one written in the macro and IF NOT disable all workbooks opening functions and/or quit Excel application – i.e. close Excel altogether? The idea behind is that my XL files could run only on one computer – sort of soft-key. If files are copied and user wants to run it on another computer to make him feel sorry. |
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