Prevent Acrobat Reader from linearizing while save

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   Hi,
The Acrobat Reader seems to manipulate (linearize) PDF documents while saving. I need to keep the exact structure of the document even if the user saves the document (without changing anything). Acrobat Reader does not linearize, if the document is signed (that is good). But of several reasons, I can not sign the document.
Is there another secure way to prevent Acrobat Reader from linearizion? Any flag or information to add?
Thank you,
Kukulkan

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kukulkan Members Profile Find Members Posts Team Player Joined: 02 Mar 06 Location: Germany Status: Offline Points: 20	Post Options Post Reply Quote kukulkan Report Post Thanks(0) Quote Reply Topic: Prevent Acrobat Reader from linearizing while save Posted: 22 Mar 11 at 10:15AM
	Hi, The Acrobat Reader seems to manipulate (linearize) PDF documents while saving. I need to keep the exact structure of the document even if the user saves the document (without changing anything). Acrobat Reader does not linearize, if the document is signed (that is good). But of several reasons, I can not sign the document. Is there another secure way to prevent Acrobat Reader from linearizion? Any flag or information to add? Thank you, Kukulkan

Ingo Members Profile Find Members Posts Moderator Group Joined: 29 Oct 05 Status: Offline Points: 3530	Post Options Post Reply Quote Ingo Report Post Thanks(0) Quote Reply Posted: 22 Mar 11 at 10:24AM
	Hi! I think using a main password should solve the problem? Cheers, Ingo

kukulkan Members Profile Find Members Posts Team Player Joined: 02 Mar 06 Location: Germany Status: Offline Points: 20	Post Options Post Reply Quote kukulkan Report Post Thanks(0) Quote Reply Posted: 22 Mar 11 at 10:50AM
	Hi Ingo, Thank you for your quick reply. The problem is, that we like to send many document to employees and others. In many cases, we do not have any additional contact. Upon this, we can not provide a password for everyone of them. Not even, if it was always the same. Or did I misunderstood something? The Acrobat Reader seems to be the only PDF reader who wants to linearize the documents. Neither Foxit nor SumatraPDF etc. are doing like that. Is there any other way to prevent Acrobat Reader from such? Removing the "CanChange" permission is not working to prevent from linearizion. Kukulkan

kukulkan Members Profile Find Members Posts Team Player Joined: 02 Mar 06 Location: Germany Status: Offline Points: 20	Post Options Post Reply Quote kukulkan Report Post Thanks(0) Quote Reply Posted: 22 Mar 11 at 11:11AM
	Ok, I found out what you mean. Set only a password against manipulation. This works good, as Acrobat Reader does not try to linearize this documents anymore. The problem is, that we get normal (unencrypted) PDF. After adding a small additional information, we need to set this password (or flag). But this seems to manipulate the objects that are already included. This is not allowed for us (as they are already hashed using SHA256). This would destroy our integrity information (we do not use the PDF functions for that). Are there any other values that we can set to prevent linearizion? How is a PDF marked as PDF/A? Would such a mark prevent linearizion? Kukulkan