Report code 2007, of the Appearance Integrity Report, from electronic signature.

[APenNameAndThatA]

Hi

When I try to sign documents by visibly certifying them, I get a warning box called "Appearnace Integrity Report" and it says that the "Report code" is "2007" and the "Description" is "Page content may silently change." I wrote a word document from a template, sent it to the person who proof reads what I write, got it back, changed it a bit, and converted it to a PDF. The document was never a form, and no, I don't want to send it to Adobe so they can see what went wrong. What to do? Thanks. 

[Amal.]

Hi @APenNameAndThatA 

Hope you are doing well and Thanks for reaching out.

Please go through the correct answer marked in the similar discussion https://answers.acrobatusers.com/APPEARANCE-INTEGRITY-REPORT-q204358.aspx and see if that helps.

Regards

Amal

[APenNameAndThatA]

Thank you for your effort. Unfortunately, that answer does not help as my document was never a form.

[Amal.]

Hi there

Sorry to keep you waiting.

The Appearance Integrity Report analyzes the document and finds any items or features that could possibly alter the document without the user knowing. If you see any error codes it means that it is not guaranteed the user signed what they viewed.

One requirement (in some countries, by law) with digital signatures is that the signer signs what they see, and only what they see (this is the integrity of appearance). Many PDF features (such as Dynamic XFA forms, JavaScript, non-embedded fonts, etc…) can alter the appearance of a PDF document at any time, and that’s why the integrity of appearance is NOT ensured with any PDF that has any feature that could modify the document. The Appearance Integrity Report flags these to because in many cases they could not be considered legal as the user could have signed something they couldn’t see.

The error 2007 described that the document author has enabled image interpolation. Which is not allowed.

Hope this information will help.

Regards

Amal

[AlonsoCast]

Hi,

Thank for your answer. My file was created with Acrobat (duly updated); it's supposed to be a true PDF. Any other suggestions? This is very annoying.

best,

[Amal.]

Hi there

Make sure that the PDF Form can assure the integrity of appearance by removing or fixing any content that could modify the document. You can use the table below to determine what each error code means to correct the document.

Signature Report Error Codes

Dynamic features: Presentations, user-launched multimedia, JavaScript, dynamic forms, etc…
 

String	Code	Description
Document contains hidden behavior	1000	The document contains hidden actions that may not be intended or known by the end user. Actions include JavaScript actions (document open, save, etc.), playing multimedia, executing a menu item, and so  on.
Comment or form field may silently change	1001	The document contains non-signature form fields. Such fields’ visual appearances may change based on external variables.
Comment or form field may silently change	1002	The document contains comments. Comments’ visual appearances may change based on external variables.
Document may silently launch menu items	1003	The document contains named actions that may launch menu items without the user’s knowledge.
Presentation elements may change appearance	1004	Presentations are not allowed since a presentation may contain animations or other elements that may change document appearance or  behavior.
The document contains a dynamic form	1005	XFA-based (dynamic forms) documents are not allowed since such forms could alter the document’s appearance or behavior.
Document contains links to external PDFs	1006	The document links to external PDFs on the Internet, file system, or network and it has no control over the nature of that linked content. Embedded Go-To actions must not refer to external hierarchies.
Comment or form field may silently change	1007	Disallowed annot type: <annot type>. One or more form fields are associated with a 3D object, file attachment, multimedia, or other dynamic objects.
Document contains hidden behavior	1008	Disallowed action type: <action type>. The document contains hidden actions that may not be intended or known by the end user. Actions include JavaScript actions (document open, save, etc.), playing multimedia, executing a menu item, and so  on.
Document contains hidden behavior	1009	The document’s content is divided into layers that can be silently displayed or hidden on the fly.

PDF content with variable rendering: JavaScript, non-embedded fonts, etc…
 

String	Code	Description
Page content may silently change	2004	Visual elements may change based on external variables. For example, a logo may change color based on time or zoom level. No postscript XObjects allowed.
Document may not	2006	Some or all of the content is encrypted and the encryption method is not available in
open in the future		standard Acrobat installations. For example, the document may be protected by the
		Adobe Policy Server. Document contain streams encrypted using crypt filter.
Page content may	2007	The document author has enabled image interpolation. No image interpolation is
silently change		allowed.
Page content may	2009	The document uses a PDF transfer function that interprets and replaces color.  For
silently change		example, it could replace black with white. Extended graphic state should not use the TR
		key
Page content may	2010	The document uses a PDF transfer function that interprets and replaces color.  For
silently change		example, it could replace black with white. If present, the extended graphic state’s TR2
		key must be set to default
Page content may	2011	The document’s extended graphic state uses the FL key. The key is a number  that
silently change		indicates how much flatness tolerance should exist when drawing objects. Content may
		display differently from Acrobat to other applications
Page content may	2012	Image XObject must not contain an alternate version
silently change
Text appearance may silently change	2013	Document contains non-embedded fonts. When the document opens on a system that does not have the requisite fonts, Acrobat will replace them with some other font. Users should always turn on font-related warnings.
Text appearance may silently change	2014	Disallowed font type: <font type>. True type and TrueType-based OpenType fonts are not allowed because they are programs and may change the document’s appearance based on external variables.

External content: Hyperlinks, alternate images, linked files, etc…
 

String	Code	Description
Document links to external content	3000	Document links to images not in the PDF. No external XObjects allowed.
Document links to external content	3001	Document links to images not in the PDF that are used as alternates. For example, an alternate, high resolution images might be specified for printing. Images must not contain an OPI alternate version.
Document links to external content	3002	Document contains external streams. The author has flagged some PDF bytes as a stream which may get data from an external source.
Document links to external content	3003	Document links to images not in the PDF that are used as alternates. For example, an alternate, high resolution images might be specified for printing. Form XObject must not contain an OPI alternate version.

Regards

Amal

[kmpeterson]

I am also having this issue.  

As with the original poster, this is not a form.  My initial discovery for this is also not something I can share, but I recreated it in a form that I can.

It appears to occur with (some number of) images inserted in a file that is then exported to PDF.  In my case, this is macOS 14.0, and Acrobat 2023.006.20320.  The document I'm including was composed with Microsoft Word, but Apple Pages also causes this issue.  Also, the problem occurs with a file that is generated using the application's built-in "Save as PDF" functionality and also when the document is exported using the macOS Print dialog and then the save as PDF function in that utility.  Also exported the document as PostScript, ran it through the Acrobat Distiller - same issue.

It seems really hard to believe that this warning is correct.  Especially passing explicitly through a PostScript phase, I seriously doubt that it's the case that there is anything "dynamic" is this document simply related to the insertion of a PNG image.

 

[Abambo]

When I take your test file, I can correctly sign this:

Checking your signed document, I get this:

[kmpeterson]

Hi there, and thanks for the response.

One of the elements of the warning that I receive is that the document would warn any recipient that it "might" have or be altered.  Since you don't see that warning (there's no certificate chain from myself to a trusted root - that's expected) it really does look like the warning is spurious and at least on the signer side can be disregarded (in this case at least).  

I've been using cryptography long enough to not ignore warnings like this, but it does seem like I can do so here.  It'd be great if this is an error and can be fixed - but thanks again for checking on this on your end, that gives me a bit more confidence.   

[MikelKlink]

If you look at the details of the Appearance Integrity Report, you'll read "The document author has enabled image interpolation. No image interpolation is allowed."

According to the PDF spec, image interpolation is an attempt to produce a smooth transition between adjacent sample values when rendering an image whose resolution is significantly lower than that of the output device. Setting the value of the Interpolate entry in an image dictionary to true, is a way for a PDF to declare to a PDF processor that a specific image might render better if interpolation is used for this particular image. However, this is only a hint, and a PDF processor may ignore it.

Thus, different PDF viewers may or may not apply interpolation, resulting in different renderings. Furthermore, there are different interpolation algorithms and parametrizations thereof but the PDF specification does not prescribe an algorithm and parametrization to use. So even PDF viewers that do interpolate don't necessarily display the image identically.

I would propose trying to configure the document creation not to use interpolation or replacing the image by vector graphics.

[kmpeterson]

Thanks for the note.  

I think this is a bug, because if it's not possible to seal a document - which is to say, rewrite it in an immutable format - in the post-processing (rendering) stage, the application has a defect.  If one is attempting to certify a document (by hashing the content and then signing the result) it's reasonable to expect that an end user has decided that any interactivity should be eliminated in favor of a valid signature.  If not, the ability to specify an option to process the file this way as part of the signature process is the only alternative to simply indicating that a signature can't be trusted.

To give credit where credit is due, though, because the artwork was created in Illustrator I am able to export the illustration as SVG - and the resulting PDF does not throw this warning and is thus valid.  This makes sense, and I appreciate your suggestion. 

However, it makes sense to me because I understand the nature of the process.  I doubt it would make sense to the vast majority of end-users trying to understand why MS-Office creates documents that aren't "fixed".

It would be really great to have someone from Adobe weigh in on this.  

Thanks again!

[MikelKlink]

Have you tried exporting to PDF/A from Word? 

PDF is a multipurpose format with several subformats optimized for specific purposes. The archival subformat PDF/A seems most appropriate in this case. 

[kmpeterson]

That might work.

My own issue is solved - having used SVG as output format for the graphics I've inserted.

But there isn't a straightforward way using the PDF export process in Word (for example) to specify the PDF format.  In macOS, there used to be a way to specify a filter during the print-to-PDF operation - which might contain the functionality to do this.  But unless one is using Acrobat or an application (certainly not Word!) that allows this specification, I still think that Acrobat should be able to ingest a PDF and (possibly requiring an intermediate step) produce an immutable PDF that can be successfully hashed and signed.  

Again, thanks for the excellent suggestions; I'd hope this would be seen as a bug by the Acrobat team.