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Distribute Excel Workbook with licence?
I have an Excel Workbook I want to distribute. I want to copy protect it. I
want to be able to email/post it to users, on first use they will be prompted to enter a code, distributed with the workbook, they will then connect to the web, and receive an 'unlock' key. The web side of things will need to keep count of how many licences they have bought. Any ideas? I thought of doing this via a small vb app, then using one of the many 3rd party protection systems to protect the vb app, which will in turn open the workbook (perhaps with an encrypted password?). Security isn't massively important, this doesn't need to be to banking standards. I just want to track who has paid for it and prevent casual copying. It isn't a mass market product to I doubt it'll appear on Warez sites. The data in the spreadsheet isn't important, it's the structure and formulae etc. The data isn't sensitive. Yours, Mike MacSween |
Distribute Excel Workbook with licence?
copy protection on workbooks is so weak, there isn't a lot of use in getting
carried away with it. Any VBA based solution can be overcome by disabling macros for a start. Any password can be bypassed with a password cracker - many of which are available on the web. Files can be copied using Explorer/the command window, so not sure how you intend to copy protect it. If the structure and the formulas are what is important, that would be the hardest to protect if the user needs to able to type things in the workbook. You would need to put critical logic into a compiled DLL or com addin or something like that. -- Regards, Tom Ogilvy "Mike MacSween" wrote in message ... I have an Excel Workbook I want to distribute. I want to copy protect it. I want to be able to email/post it to users, on first use they will be prompted to enter a code, distributed with the workbook, they will then connect to the web, and receive an 'unlock' key. The web side of things will need to keep count of how many licences they have bought. Any ideas? I thought of doing this via a small vb app, then using one of the many 3rd party protection systems to protect the vb app, which will in turn open the workbook (perhaps with an encrypted password?). Security isn't massively important, this doesn't need to be to banking standards. I just want to track who has paid for it and prevent casual copying. It isn't a mass market product to I doubt it'll appear on Warez sites. The data in the spreadsheet isn't important, it's the structure and formulae etc. The data isn't sensitive. Yours, Mike MacSween |
Distribute Excel Workbook with licence?
Mike MacSween wrote:
I have an Excel Workbook I want to distribute. I want to copy protect it. I want to be able to email/post it to users, on first use they will be prompted to enter a code, distributed with the workbook, they will then connect to the web, and receive an 'unlock' key. Probably best to write some custom code that can then output Excel files (if you really want to be able to use Excel). |
Distribute Excel Workbook with licence?
"Mike MacSween" wrote in message . ..
I have an Excel Workbook I want to distribute. I want to copy protect it. I want to be able to email/post it to users, on first use they will be prompted to enter a code, distributed with the workbook, they will then connect to the web, and receive an 'unlock' key. The web side of things will need to keep count of how many licences they have bought. This is entirely feasible. I would suggest that you impliment this solution with Macros and protect it with standard MS Excel password protection. Any ideas? I thought of doing this via a small vb app, then using one of the many 3rd party protection systems to protect the vb app, which will in turn open the workbook (perhaps with an encrypted password?). Security isn't massively important, this doesn't need to be to banking standards. I just want to track who has paid for it and prevent casual copying. It isn't a mass market product to I doubt it'll appear on Warez sites. The data in the spreadsheet isn't important, it's the structure and formulae etc. The data isn't sensitive. Yours, Mike MacSween If security were more important, you might consider creating an Excel Add In. -- http://www.intertek.org.uk |
Distribute Excel Workbook with licence?
If security were more important, you might consider creating an Excel Add In. A standard Excel add-in (XLA file) is no more secure that a workbook. For real security, you need to use an XLL or a COM add-in. -- Cordially, Chip Pearson Microsoft MVP - Excel Pearson Software Consulting, LLC www.cpearson.com "Alert" wrote in message om... "Mike MacSween" wrote in message . .. I have an Excel Workbook I want to distribute. I want to copy protect it. I want to be able to email/post it to users, on first use they will be prompted to enter a code, distributed with the workbook, they will then connect to the web, and receive an 'unlock' key. The web side of things will need to keep count of how many licences they have bought. This is entirely feasible. I would suggest that you impliment this solution with Macros and protect it with standard MS Excel password protection. Any ideas? I thought of doing this via a small vb app, then using one of the many 3rd party protection systems to protect the vb app, which will in turn open the workbook (perhaps with an encrypted password?). Security isn't massively important, this doesn't need to be to banking standards. I just want to track who has paid for it and prevent casual copying. It isn't a mass market product to I doubt it'll appear on Warez sites. The data in the spreadsheet isn't important, it's the structure and formulae etc. The data isn't sensitive. Yours, Mike MacSween If security were more important, you might consider creating an Excel Add In. -- http://www.intertek.org.uk |
Distribute Excel Workbook with licence?
Hello Chip,
A standard Excel add-in (XLA file) is no more secure that a workbook. Is it true that Excel 97 Add-ins even without VBA-Passwords are secure? Do you know how securing the workbook/addin was done in Excel 97. I hate to say that but I am too young to know ;) best regards arno |
Distribute Excel Workbook with licence?
"Dave Peterson" wrote in message
... I'm not Chip, but until he returns... Excel Addins (*.xla's) are not secure at all--and without a password, even the most mildly curious will be able to see/modify your code. Addins with passwords are only slightly better. The passwords will stop the honest--but not the determined. And there are password breakers all over the internet. With enough money (about 50 USD, IIRC), anyone can see and modify Not talking about this particular case, but I frequently hear the 'you can buy a password cracker so the password is useless' statement. I bought one yesterday and ran it against the file open password on an Excel file. I'd used a deliberately obscure, completely non alphanumeric long password. It went through the dictionary attack (and failed, obviously) in 5 seconds. It then started on the brute force attack (well, a sort of refined brute force). I turned it off after a few hours when it was still running bXXXXXXX. As a matter of fact when I tried to set it up to so that it would (eventually) get my password it complained that it would take too long, and shortened the length of the passwords it would try, basically guaranteeing it wouldn't ever get mine. It estimated 45,000 days! I think it's a myth. Sure, if somebody uses their first name+last name as a password, that's easy to crack. I've 'cracked' that often enough when I've needed to log on as a user and I know their name. But I really don't think that passwords are as useless as everybody says. If you know how to make a very strong password then you can do a lot. Mike |
Distribute Excel Workbook with licence?
This is interesting, but I've seen code/algorithms that can unprotect a VBA
project in seconds--no matter what the the password is. It was disappointing that it was that easy. Mike MacSween wrote: "Dave Peterson" wrote in message ... I'm not Chip, but until he returns... Excel Addins (*.xla's) are not secure at all--and without a password, even the most mildly curious will be able to see/modify your code. Addins with passwords are only slightly better. The passwords will stop the honest--but not the determined. And there are password breakers all over the internet. With enough money (about 50 USD, IIRC), anyone can see and modify Not talking about this particular case, but I frequently hear the 'you can buy a password cracker so the password is useless' statement. I bought one yesterday and ran it against the file open password on an Excel file. I'd used a deliberately obscure, completely non alphanumeric long password. It went through the dictionary attack (and failed, obviously) in 5 seconds. It then started on the brute force attack (well, a sort of refined brute force). I turned it off after a few hours when it was still running bXXXXXXX. As a matter of fact when I tried to set it up to so that it would (eventually) get my password it complained that it would take too long, and shortened the length of the passwords it would try, basically guaranteeing it wouldn't ever get mine. It estimated 45,000 days! I think it's a myth. Sure, if somebody uses their first name+last name as a password, that's easy to crack. I've 'cracked' that often enough when I've needed to log on as a user and I know their name. But I really don't think that passwords are as useless as everybody says. If you know how to make a very strong password then you can do a lot. Mike -- Dave Peterson |
Distribute Excel Workbook with licence?
Hi Mike,
you are not right. Esp. removing the VBA-password is very, very, easy. E. g. Sheet protection passwords are cracked without knowing the password simply by using binary numbers 0011010100, in the end one always fits. This is why I asked how Excel **97** did the job. arno |
Distribute Excel Workbook with licence?
I think it's a myth I use VBA Key from PassWare ($45), and it breaks VBA passwords in a matter of a few seconds. For example, a 16 character mixed alpha/numeric/special char password was broken in Excel 2003 in about 3 seconds. Of course, it doesn't recover the password that was actually used to protect the project, only a password that will work to open the project. The principle still stands: password protection is useless against users who really want to get to your code. If security is critical, write a COM Add-In. -- Cordially, Chip Pearson Microsoft MVP - Excel Pearson Software Consulting, LLC www.cpearson.com "Mike MacSween" wrote in message ... "Dave Peterson" wrote in message ... I'm not Chip, but until he returns... Excel Addins (*.xla's) are not secure at all--and without a password, even the most mildly curious will be able to see/modify your code. Addins with passwords are only slightly better. The passwords will stop the honest--but not the determined. And there are password breakers all over the internet. With enough money (about 50 USD, IIRC), anyone can see and modify Not talking about this particular case, but I frequently hear the 'you can buy a password cracker so the password is useless' statement. I bought one yesterday and ran it against the file open password on an Excel file. I'd used a deliberately obscure, completely non alphanumeric long password. It went through the dictionary attack (and failed, obviously) in 5 seconds. It then started on the brute force attack (well, a sort of refined brute force). I turned it off after a few hours when it was still running bXXXXXXX. As a matter of fact when I tried to set it up to so that it would (eventually) get my password it complained that it would take too long, and shortened the length of the passwords it would try, basically guaranteeing it wouldn't ever get mine. It estimated 45,000 days! I think it's a myth. Sure, if somebody uses their first name+last name as a password, that's easy to crack. I've 'cracked' that often enough when I've needed to log on as a user and I know their name. But I really don't think that passwords are as useless as everybody says. If you know how to make a very strong password then you can do a lot. Mike |
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