Re: protect downloaded files?
It's pretty impossible to have your cake and eat it too.
That's the crux if you ask me. This is a philosophical question
more than anything else. First off, duplication/modification is
impossible to prevent.
I think the closest you could get would be a md5 type deal.
And that's pretty much it. You could verify if it was pretty
likely that this document is the same as the original, but
there is no way to show someone something and then
never have shown them. Well, I guess if you get into the
whole quantum physics there are ways, but basically what
is being asked breaks the more obvious laws of physics.
All that said, a large percent of people won't even try to
thwart the most minimal of measures, so nice try on the
read0nly bit. [=
Like Dave sorta said, PDF is probably toughest to crack,
'tween word and pdf. But best is if you don't give it
to people you don't want editing it. Akin to the whole,
safest network is the unplugged one, or abstinence.
Lovely thought games, not too practical...
Sorry, I just deleted a PDF password cracking util
and so... well, never mind. Ok, mind. PDF over Word,
hands down ('sides abstinence OC).
Adobe has put some thought into it.
:dEnn
On 4/20/06, Dave Watts [EMAIL PROTECTED] wrote:
Isn't there a way to password lock a PDF file where it can
still be viewed but not exported into something else? No
matter what though there will always be a way around anything
done just depends on how motivated someone is.
Yes, you can apply granular controls to limit what someone can do with a
PDF, and you can protect those settings using encryption. You can
digitally
sign PDFs to guarantee that documents haven't been changed, and you can
apply digital signatures to allow specific types of changes but guarantee
the overall validity of the document.
Dave Watts, CTO, Fig Leaf Software
http://www.figleaf.com/
Fig Leaf Software provides the highest caliber vendor-authorized
instruction at our training centers in Washington DC, Atlanta,
Chicago, Baltimore, Northern Virginia, or on-site at your location.
Visit http://training.figleaf.com/ for more information!
~|
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RE: protect downloaded files?
Once a client downloads the file, they can easily change the attributes of the file From read-only to Normal and modify them anyway. Just can not do that on the files on the server. But to answer your question, sorry I do not know a way other than making them all PDF files however there are ways to convert a PDF file to another type and then be Able to make changes. -Original Message- From: Ray Champagne [mailto:[EMAIL PROTECTED] Sent: Thursday, April 20, 2006 4:42 PM To: CF-Talk Subject: protect downloaded files? Anyone know if there is a surefire way to make all downloaded files read-only? We have a client that wants to have files available to download, but the original author doesn't want to have them be able to be edited. We're talking PowerPoint, Word, PDF files here, BTW. Any advice on how to make this happen would be appreciated. We've found that even using the Read Only attribute in the file properties doesn't persist once a copy has been downloaded to the client. TIA Ray ~| Message: http://www.houseoffusion.com/lists.cfm/link=i:4:238325 Archives: http://www.houseoffusion.com/cf_lists/threads.cfm/4 Subscription: http://www.houseoffusion.com/lists.cfm/link=s:4 Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=11502.10531.4 Donations Support: http://www.houseoffusion.com/tiny.cfm/54
Re: protect downloaded files?
Um, no. And even if you could force a downloaded file to be read-only, they are still easily edited, by changing the file properties or saving it as another name. Unless you can force the users to buy and install DRM software (and use it), you are out of luck. On 4/20/06, Ray Champagne [EMAIL PROTECTED] wrote: Anyone know if there is a surefire way to make all downloaded files read-only? We have a client that wants to have files available to download, but the original author doesn't want to have them be able to be edited. We're talking PowerPoint, Word, PDF files here, BTW. Any advice on how to make this happen would be appreciated. We've found that even using the Read Only attribute in the file properties doesn't persist once a copy has been downloaded to the client. ~| Message: http://www.houseoffusion.com/lists.cfm/link=i:4:238326 Archives: http://www.houseoffusion.com/cf_lists/threads.cfm/4 Subscription: http://www.houseoffusion.com/lists.cfm/link=s:4 Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=11502.10531.4 Donations Support: http://www.houseoffusion.com/tiny.cfm/54
RE: protect downloaded files?
I don't think you can unless you use the embedded features to protect the documents. However, as with all items, anytime there's security there's usually some way around it. Setting the file Read only attribute would not really do much if someone knew how to turn it off, or they could just save it as a different filename. For things like Powerpoint, you could save it as a .pps file which is just the show without editing capabilities. However, I'd imagine there's some sort of utility to make it editable again. Same thing with PDFs. You can set a password on it but there's probably a way around it. John Burns Certified Advanced ColdFusion MX Developer Wyle Laboratories, Inc. | Web Developer -Original Message- From: Ray Champagne [mailto:[EMAIL PROTECTED] Sent: Thursday, April 20, 2006 4:42 PM To: CF-Talk Subject: protect downloaded files? Anyone know if there is a surefire way to make all downloaded files read-only? We have a client that wants to have files available to download, but the original author doesn't want to have them be able to be edited. We're talking PowerPoint, Word, PDF files here, BTW. Any advice on how to make this happen would be appreciated. We've found that even using the Read Only attribute in the file properties doesn't persist once a copy has been downloaded to the client. TIA Ray ~| Message: http://www.houseoffusion.com/lists.cfm/link=i:4:238327 Archives: http://www.houseoffusion.com/cf_lists/threads.cfm/4 Subscription: http://www.houseoffusion.com/lists.cfm/link=s:4 Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=89.70.4 Donations Support: http://www.houseoffusion.com/tiny.cfm/54
RE: protect downloaded files?
That's not possible for most files. PDF does have the option of password protecting files to provide varying levels of access, I suspect that Powerpoint might offer the same thing. For most files, though, once the user has it they can do anything they want with it. !//-- andy matthews web developer ICGLink, Inc. [EMAIL PROTECTED] 615.370.1530 x737 --//- -Original Message- From: Ray Champagne [mailto:[EMAIL PROTECTED] Sent: Thursday, April 20, 2006 3:42 PM To: CF-Talk Subject: protect downloaded files? Anyone know if there is a surefire way to make all downloaded files read-only? We have a client that wants to have files available to download, but the original author doesn't want to have them be able to be edited. We're talking PowerPoint, Word, PDF files here, BTW. Any advice on how to make this happen would be appreciated. We've found that even using the Read Only attribute in the file properties doesn't persist once a copy has been downloaded to the client. TIA Ray ~| Message: http://www.houseoffusion.com/lists.cfm/link=i:4:238328 Archives: http://www.houseoffusion.com/cf_lists/threads.cfm/4 Subscription: http://www.houseoffusion.com/lists.cfm/link=s:4 Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=89.70.4 Donations Support: http://www.houseoffusion.com/tiny.cfm/54
Re: protect downloaded files?
Isn't there a way to password lock a PDF file where it can still be viewed but not exported into something else? No matter what though there will always be a way around anything done just depends on how motivated someone is. On 4/20/06, Adkins, Randy [EMAIL PROTECTED] wrote: But to answer your question, sorry I do not know a way other than making them all PDF files however there are ways to convert a PDF file to another type and then be Able to make changes. -Original Message- From: Ray Champagne [mailto:[EMAIL PROTECTED] Sent: Thursday, April 20, 2006 4:42 PM To: CF-Talk Subject: protect downloaded files? Anyone know if there is a surefire way to make all downloaded files read-only? We have a client that wants to have files available to download, but the original author doesn't want to have them be able to be edited. We're talking PowerPoint, Word, PDF files here, BTW. Any advice on how to make this happen would be appreciated. We've found that even using the Read Only attribute in the file properties doesn't persist once a copy has been downloaded to the client. TIA Ray ~| Message: http://www.houseoffusion.com/lists.cfm/link=i:4:238329 Archives: http://www.houseoffusion.com/cf_lists/threads.cfm/4 Subscription: http://www.houseoffusion.com/lists.cfm/link=s:4 Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=11502.10531.4 Donations Support: http://www.houseoffusion.com/tiny.cfm/54
Re: protect downloaded files?
Thanks Randy: FYI, just for future knowledge, we found that even if you change the attributes to Read Only on the server copy, it gets changed to Normal once downloaded. One doesn't even have to touch the attributes to get it back to normal. Seems a little silly to even have that option if it doesn't work, or is extremely easy to alter when not dealing with server/client relationships. Ray Adkins, Randy wrote: Once a client downloads the file, they can easily change the attributes of the file From read-only to Normal and modify them anyway. Just can not do that on the files on the server. But to answer your question, sorry I do not know a way other than making them all PDF files however there are ways to convert a PDF file to another type and then be Able to make changes. -Original Message- From: Ray Champagne [mailto:[EMAIL PROTECTED] Sent: Thursday, April 20, 2006 4:42 PM To: CF-Talk Subject: protect downloaded files? Anyone know if there is a surefire way to make all downloaded files read-only? We have a client that wants to have files available to download, but the original author doesn't want to have them be able to be edited. We're talking PowerPoint, Word, PDF files here, BTW. Any advice on how to make this happen would be appreciated. We've found that even using the Read Only attribute in the file properties doesn't persist once a copy has been downloaded to the client. TIA Ray ~| Message: http://www.houseoffusion.com/lists.cfm/link=i:4:238330 Archives: http://www.houseoffusion.com/cf_lists/threads.cfm/4 Subscription: http://www.houseoffusion.com/lists.cfm/link=s:4 Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=11502.10531.4 Donations Support: http://www.houseoffusion.com/tiny.cfm/54
RE: protect downloaded files?
Anyone know if there is a surefire way to make all downloaded files read-only? Surefire --- no, but more difficult yes. Both word and PDF have internal locking capabilities that should get you what you want. I'm sure they are not perfect, but should prevent all but the most dedicated hacker from accessing and modifying the files. -- Ian Skinner Web Programmer BloodSource www.BloodSource.org Sacramento, CA - | 1 | | - Binary Soduko | | | - C code. C code run. Run code run. Please! - Cynthia Dunning Confidentiality Notice: This message including any attachments is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender and delete any copies of this message. ~| Message: http://www.houseoffusion.com/lists.cfm/link=i:4:238331 Archives: http://www.houseoffusion.com/cf_lists/threads.cfm/4 Subscription: http://www.houseoffusion.com/lists.cfm/link=s:4 Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=89.70.4 Donations Support: http://www.houseoffusion.com/tiny.cfm/54
Re: protect downloaded files?
For Word, are you talking about the Read Only attribute? Ian Skinner wrote: Anyone know if there is a surefire way to make all downloaded files read-only? Surefire --- no, but more difficult yes. Both word and PDF have internal locking capabilities that should get you what you want. I'm sure they are not perfect, but should prevent all but the most dedicated hacker from accessing and modifying the files. -- Ian Skinner Web Programmer BloodSource www.BloodSource.org Sacramento, CA - | 1 | | - Binary Soduko | | | - C code. C code run. Run code run. Please! - Cynthia Dunning Confidentiality Notice: This message including any attachments is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender and delete any copies of this message. ~| Message: http://www.houseoffusion.com/lists.cfm/link=i:4:238332 Archives: http://www.houseoffusion.com/cf_lists/threads.cfm/4 Subscription: http://www.houseoffusion.com/lists.cfm/link=s:4 Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=89.70.4 Donations Support: http://www.houseoffusion.com/tiny.cfm/54
RE: protect downloaded files?
Anyone know if there is a surefire way to make all downloaded files read-only? You could convert everything to image files. Of course that would still only slow them down, and bloat the download size. But at least they couldn't copy and past or Save As another type. Some good OCR software might even hack that easily I guess... ~Brad ~| Message: http://www.houseoffusion.com/lists.cfm/link=i:4:238333 Archives: http://www.houseoffusion.com/cf_lists/threads.cfm/4 Subscription: http://www.houseoffusion.com/lists.cfm/link=s:4 Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=89.70.4 Donations Support: http://www.houseoffusion.com/tiny.cfm/54
RE: protect downloaded files?
From a quick glance at Word's help. Protect a document from unauthorized changes OPTION ONE Seal your document with a digital certificate You digitally sign a file or a macro project by using a digital certificate. If you don't already have a digital certificate, you must obtain one. How? You can obtain a digital certificate from a commercial certification authority, such as VeriSign, Inc., or from your internal security administrator or Information Technology (IT) professional. Or, you can create a digital signature yourself using the Selfcert.exe tool. To learn more about certification authorities that offer services for Microsoft products, see the Microsoft Security Advisor Web site. Notes The hyperlink in this topic goes to the Web. You can switch back to Help at any time. Because a digital certificate you create yourself isn't issued by a formal certification authority, macro projects signed by using such a certificate are referred to as self-signed projects. Depending on how Microsoft Office digital-signature features are being used in your organization, you might be prevented from using such a certificate, and other users might not be able to run self-signed macros for security reasons. On the Tools menu, click Options, and click the Security tab. Click Digital signatures. Click Add. Select the certificate you want to add, and then click OK. OPTION TWO Require a password to open or modify a document When you create a password, write it down and keep it in a secure place. If you lose the password, you cannot open or gain access to the password-protected document. Open the file. On the Tools menu, click Options, and then click Security. Do one of the following: Create a password to open In the Password to open box, type a password, and then click OK. In the Reenter password to open box, type the password again, and then click OK. Create a password to modify In the Password to modify box, type a password, and then click OK. In the Reenter password to modify box, type the password again, and then click OK. Tip To create a long password â up to 255 characters â click Advanced, and select an RC4 encryption type. -- Ian Skinner Web Programmer BloodSource www.BloodSource.org Sacramento, CA - | 1 | | - Binary Soduko | | | - C code. C code run. Run code run. Please! - Cynthia Dunning Confidentiality Notice: This message including any attachments is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender and delete any copies of this message. ~| Message: http://www.houseoffusion.com/lists.cfm/link=i:4:238335 Archives: http://www.houseoffusion.com/cf_lists/threads.cfm/4 Subscription: http://www.houseoffusion.com/lists.cfm/link=s:4 Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=11502.10531.4 Donations Support: http://www.houseoffusion.com/tiny.cfm/54
RE: protect downloaded files?
For Word, are you talking about the Read Only attribute? I'm not sure. I am not talking about the file system Read Only, but an internal Word feature, something like Protect Document. That can be set with a password. So only those who know the password can modify the document. I know that PDF has a similar feature. Nether are perfect, but they do require some effort to get around. -- Ian Skinner Web Programmer BloodSource www.BloodSource.org Sacramento, CA - | 1 | | - Binary Soduko | | | - C code. C code run. Run code run. Please! - Cynthia Dunning Confidentiality Notice: This message including any attachments is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender and delete any copies of this message. ~| Message: http://www.houseoffusion.com/lists.cfm/link=i:4:238336 Archives: http://www.houseoffusion.com/cf_lists/threads.cfm/4 Subscription: http://www.houseoffusion.com/lists.cfm/link=s:4 Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=89.70.4 Donations Support: http://www.houseoffusion.com/tiny.cfm/54
RE: protect downloaded files?
Well maybe that doesn't do much for word. It will prevent someone from changing the original file, but one can save as to a new file at will. So you might be left with coverting everything to PDF which has somewhat more extensive internal protections. -- Ian Skinner Web Programmer BloodSource www.BloodSource.org Sacramento, CA - | 1 | | - Binary Soduko | | | - C code. C code run. Run code run. Please! - Cynthia Dunning Confidentiality Notice: This message including any attachments is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender and delete any copies of this message. ~| Message: http://www.houseoffusion.com/lists.cfm/link=i:4:238337 Archives: http://www.houseoffusion.com/cf_lists/threads.cfm/4 Subscription: http://www.houseoffusion.com/lists.cfm/link=s:4 Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=11502.10531.4 Donations Support: http://www.houseoffusion.com/tiny.cfm/54
RE: protect downloaded files?
Isn't there a way to password lock a PDF file where it can still be viewed but not exported into something else? No matter what though there will always be a way around anything done just depends on how motivated someone is. Yes, you can apply granular controls to limit what someone can do with a PDF, and you can protect those settings using encryption. You can digitally sign PDFs to guarantee that documents haven't been changed, and you can apply digital signatures to allow specific types of changes but guarantee the overall validity of the document. Dave Watts, CTO, Fig Leaf Software http://www.figleaf.com/ Fig Leaf Software provides the highest caliber vendor-authorized instruction at our training centers in Washington DC, Atlanta, Chicago, Baltimore, Northern Virginia, or on-site at your location. Visit http://training.figleaf.com/ for more information! ~| Message: http://www.houseoffusion.com/lists.cfm/link=i:4:238342 Archives: http://www.houseoffusion.com/cf_lists/threads.cfm/4 Subscription: http://www.houseoffusion.com/lists.cfm/link=s:4 Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=89.70.4 Donations Support: http://www.houseoffusion.com/tiny.cfm/54
