How to Copy Protect a File? at DVinfo.net

Warren Kawamoto · September 15th, 2014, 12:14 PM

Is there a way to allow a video file to be moved, but not allowed to be duplicated or copied? How is this done? For example, if I had a video file on a usb thumbdrive for a client, but I don't want him to copy and distribute it. Cut and pasting it to another drive is ok as long as it's moved without duplicating it?

Andrew Smith · September 16th, 2014, 01:43 AM

No.

Andrew

Jim Andrada · September 19th, 2014, 12:24 PM

Well you could encrypt it but then nobody could view it. Fundamentally if you can see it on a computer you can get hold of it on a computer.

Warren Kawamoto · September 21st, 2014, 10:40 AM

I right click on the file, properties/security/edit, then deny full control except "read." This prevents copying and altering the file. However, I can't move the file around, which is what I wanted to do. For now, I can put a file onto a flashdrive, then lock it with the steps above. Client would then have to insert the flashdrive to their device and play it only from the flashdrive.

Jim Michael · September 21st, 2014, 03:04 PM

Anyone can copy the flash drive contents to other media. Those attributes are easily changed on writable media. As for using javascript on web interfaces it's easy to examine the code and determine where the file is and download it.

In general, rather than try to prevent copying it's better to eliminate the motivation for doing so and that's usually related to a change in the underlying business model. E.g. make compensation a attribute of the service rather than the end product.

Streaming might be an option but you're probably better off using a third party provider rather than trying to roll your own.

Jim Andrada · September 24th, 2014, 09:11 PM

+1 for what Jim said - if you can read it you can copy it. All it takes to copy something is read, write, read, write,...

Barry Hunter · September 25th, 2014, 12:55 AM

Something that I have never tried but in theory "Might" work on a DVD! At the end of a video sequence, include say 15 min of "Black" When you make the DVD put a small scratch on the outermost part of the recorded data, where the "Black" is! If you then try to copy it the software reading will report that it can`t read all the data & will therefore refuse to copy it, however, the DVD will still play in the normal way!
Thoughts anyone?

Paul R Johnson · September 25th, 2014, 01:20 AM

Now that is a great idea! Only copiers and complete file readers would get annoyed, and it would as you say play in an ordinary player. Clever!

Jim Andrada · September 27th, 2014, 01:34 PM

Well, block by block read/write would still copy it. And the OP was referring to a Thumb drive as opposed to a DVD.

Regardless, short of encryption, there's no way to prevent someone who badly enough wants to copy something from doing so.

September 15th, 2014, 12:14 PM	#1
Warren Kawamoto Trustee Join Date: Nov 2006 Location: Honolulu, HI Posts: 1,435	How to Copy Protect a File? Is there a way to allow a video file to be moved, but not allowed to be duplicated or copied? How is this done? For example, if I had a video file on a usb thumbdrive for a client, but I don't want him to copy and distribute it. Cut and pasting it to another drive is ok as long as it's moved without duplicating it?

September 16th, 2014, 01:43 AM	#2
Andrew Smith Equal Opportunity Offender Join Date: Feb 2009 Location: Brisbane, Australia Posts: 3,066	Re: How to Copy Protect a File? No. Andrew

September 19th, 2014, 12:24 PM	#3
Jim Andrada Inner Circle Join Date: Feb 2007 Location: Tucson AZ Posts: 2,211	Re: How to Copy Protect a File? Well you could encrypt it but then nobody could view it. Fundamentally if you can see it on a computer you can get hold of it on a computer.

September 21st, 2014, 10:40 AM	#4
Warren Kawamoto Trustee Join Date: Nov 2006 Location: Honolulu, HI Posts: 1,435	Re: How to Copy Protect a File? I right click on the file, properties/security/edit, then deny full control except "read." This prevents copying and altering the file. However, I can't move the file around, which is what I wanted to do. For now, I can put a file onto a flashdrive, then lock it with the steps above. Client would then have to insert the flashdrive to their device and play it only from the flashdrive.

September 21st, 2014, 03:04 PM	#5
Jim Michael Major Player Join Date: Dec 2005 Posts: 895	Re: How to Copy Protect a File? Anyone can copy the flash drive contents to other media. Those attributes are easily changed on writable media. As for using javascript on web interfaces it's easy to examine the code and determine where the file is and download it. In general, rather than try to prevent copying it's better to eliminate the motivation for doing so and that's usually related to a change in the underlying business model. E.g. make compensation a attribute of the service rather than the end product. Streaming might be an option but you're probably better off using a third party provider rather than trying to roll your own.

September 24th, 2014, 09:11 PM	#6
Jim Andrada Inner Circle Join Date: Feb 2007 Location: Tucson AZ Posts: 2,211	Re: How to Copy Protect a File? +1 for what Jim said - if you can read it you can copy it. All it takes to copy something is read, write, read, write,...

September 25th, 2014, 12:55 AM	#7
Barry Hunter Regular Crew Join Date: Jan 2012 Location: Newton Abbot Devon Posts: 46	Re: How to Copy Protect a File? Something that I have never tried but in theory "Might" work on a DVD! At the end of a video sequence, include say 15 min of "Black" When you make the DVD put a small scratch on the outermost part of the recorded data, where the "Black" is! If you then try to copy it the software reading will report that it can`t read all the data & will therefore refuse to copy it, however, the DVD will still play in the normal way! Thoughts anyone?

September 25th, 2014, 01:20 AM	#8
Paul R Johnson Inner Circle Join Date: Nov 2005 Location: Lowestoft - UK Posts: 4,045	Re: How to Copy Protect a File? Now that is a great idea! Only copiers and complete file readers would get annoyed, and it would as you say play in an ordinary player. Clever!

September 27th, 2014, 01:34 PM	#9
Jim Andrada Inner Circle Join Date: Feb 2007 Location: Tucson AZ Posts: 2,211	Re: How to Copy Protect a File? Well, block by block read/write would still copy it. And the OP was referring to a Thumb drive as opposed to a DVD. Regardless, short of encryption, there's no way to prevent someone who badly enough wants to copy something from doing so.