Digital signatures and combining PDFs in Acrobat X

I hope that one of you Acrobat gurus can help me out with one or more of these questions:
Is it possible to maintain digital signatures when inserting signed PDFs into another PDF?
Is it possible to remove a digital signature after a signature has been deleted from the page?
Is it possible to change the format of the date and time on a digital signature?

In the simplest sense a digital signature is a special checksum of all the bytes in the bytes in the PDF combined with all the bytes in the digital signature. If the document is changed in any way the checksum changes, so the signature becomes invalid. A valid signature ensures that the document hasn't changed since the signature was applied. That stuff that's shown on the signature field is irrelevant. It's just a pretty picture. The real stuff is going on inside the PDF where you can't see it.
Obviously it gets a lot more complext then this. The signature can be selectively applied so that the certain types of changes are allowed. A signature does not add real protection to a PDF, but Acrobat plays along with this scheme by trying to not allow changes that would invalidate the signature, and logging all modifications to the PDF.
1) There are ways to maintain the visual appearance of the signature on the page. If the permissions have been set to allow it the PDF can be flattened, which also partially removes much of the stuff that's going on internally. But this isn't always possible. I had to solve this problem once for a client, so I wrote a plug-in that strips the signature permissions from the PDF (I'll post this to www.pdfscripting.com sometime soon), after which the the PDF can be flattened, keeping the appearance. But of course, after this point the document has to be considered invalid. For example, if the document was a contract, the flattened version would be good for use in an analysis of say all contracts for a particular year, or for copying legal language to another contract, but it couldn't be used as the basis of a legal dispute.
2) I don't understand this one. Do you mean you're deleting the signature field and some of the internal digital signature stuff is still hanging around causing problems? If you own the signature (or the permissions allow), then a standard form reset will "Un-Sign" the PDF. Inserting PDF pages into another PDF will strip out all this info as well.
3) The stamp appearance is set at the time the stamp is applied, it cannot be changed after this point. It's a lot like a PDF stamp.
Thom Parker
The source for PDF Scripting Info
pdfscripting.com
The Acrobat JavaScript Reference, Use it Early and Often
http://www.adobe.com/devnet/acrobat/javascript.html
Then most important JavaScript Development tool in Acrobat
The Console Window (Video tutorial)
The Console Window(article)

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Using Digital Signatures in a PDF File | Acrobat X | Adobe TV

This video details how to use the new Sign & Certify panel for digital signatures, including the new Time Stamp Document tool, in Acrobat X Std. and Pro.
http://adobe.ly/yDHBdn

I wanted to add a scanned pdf signature to a W-9 form, and I changed the preference in Security as you suggested, but the new icon in the top tool bar is grayed out, as are all the choices within the Sign & Certify drop down. I watched movies, and looked at forums, and no one has this grayed-out issue. I have been trying to figure this out for an hour, and everything I find is a dead end.

Looking for "PDF Public-Key Digital Signature and Encryption Specification"

Hi,
i am looking for the following ("old") document:
PDF Public-Key Digital Signature and Encryption Specification
Originally i could be found here:
http://partners.adobe.com/asn/developer/acrosdk/DOCS/ppk_pdfspec.pdf
But not anymore. Does somebody of you still have it? Adobe today just offers the latest documents but i specifically need that older version.
Or is there an archive i don't know of?
Thanks for your help,
ToM

You can read the PDF 1.5 specification OR even ISO 32000-1 itself for that information. Each feature is "tagged" with the specific version in which it was introduced.
Digital Signatures were first introduced in Acrobat 4 (PDF 1.3) and have seen various improvements which each version since.

Maintaining digital signatures in single pdf

Is there a way in Acrobat 9 Pro to maintain digital signatures when combining multiple files into a single pdf? For instance, if I sign my timecard and a separate expense report, then my supervisor also countersigns both documents, I lose the signatures when combining the timecard and expense report into a single file. I believe the signatures are maintained when creating a portfolio, but can it also be accomplished in a single pdf?

I tried combining mulitple pdf documents either signed by me and/or a customer into one pdf document and the signatures were lost. However, if you combine them as a 'PDF Portfolio' instead of 'Single PDF' you'll maintain the signatures. The option is located in the right corner of the 'Combine Files' screen.

Securing Digital Signatures and none of that other stuff

Hello. I am new to getting help from highly knowledgeable people in this type of forum. This will be my second question asked. The first time response was quick, correct, and succinct. I am grateful for your help and I thank you. I will need to find out how to close out the thread I initiated wit the first question. Now my second question will allow me to cut to the chase, (provided I learned correctly what my mentors told me when responding to my first question). Here it is: I want to lock my digital signature to a PDF document without the use of a third party CA or without becoming a do it yourself CA. From my perspective it would seem that these programs or services are far more that I need. I simply need to secure, lock don my digital signature of PDF document that I send out to government agencies. It’s a one way trip. Copies of the documents are provided to members of my association, again a one way trip. I need to have my digital signature integrated into the text of the document and secure as well as the PDF document itself. That is all I want to do; no tracking, no secured return digital signatures, etc. I prefer to by a add in or an easy to use software program, but if I absolutely have to, I can work with the “cloud”. Can anybody point me in the right direction? Eally need help.
Thanks for your consideration and past assistance.
HALO

There are many different types of digital signatures. I use digital signatures that are self-signed. They cannot be verified by the people that receive them, but guarentee the documents haven't been changed since signed.
This article might help: http://help.adobe.com/en_US/acrobat/X/standard/using/WS11dd809af63f0e1e-43e0464b12b4384d3b 6-8000.html
As to your previous thread. We do not close threads usually as other people with similar issues may want to post or read the thread. You can go and mark the thread as solved.

Question from worse than Newbie about digital signatures and Adobe Reader.

1st, thanks for taking the time to even look. 2nd, We are trying to use digital signature pads with PDF documents created by Documaker 11.4. In Adobe Pro there is a setting "Extend features in Adobe Reader" that will allow users with Adobe Reader to sign the PDF documents, however our "guy" creating the forms cannot find anything like this in Documaker. I've never used Documaker before and dont have a copy to even play with, but I was hoping there was a simple "go here, click this" answer.
Any and all help is greatly appreciated.
Thanks for you time,
Jeff Holt

I'm not expert on Documaker, but I'm close to them and will try to find an answer if I can be sure of the question.
Documaker is capable of creating PDF signature markers in the output PDF. Those markers are compatible with tools like Acrobat which can sign the documents. Is your question about how to create the markers or are you doing that and finding that Acrobat Reader will not allow you to sign them?
I'd have to research Adobe's licensing for Acrobat and Reader to see if that was the issue. I know certain features in Acrobat Reader are locked down by Adobe so you have to have another product license from them to enable the feature. If that is the problem, then I'm pretty sure that Documaker has no mechanism to provide a license token to specifically enable the Acrobat Reader product.
If you can provide more specifics, I'll try to follow up. You may also contact Customer Support, if you haven't already and open a case there requesting a specific question be answered.
Best Regards.

Click for digital signature without Save PDF?

Previous versions of interactive/fillable PDFs didn't require the document to be saved once the user clicked to digitally sign. We've rendered some new PDFs with Acrobat X Pro that have a digital signature and it is requiring the user to save the file. This poses a challenge because some of these PDFs may be used on a tablet or iPad by a sales representative that is trying to collect a signature but needs to continue filling out the form beyond what the purchaser of services/products is agreeing to above that signature. There will also be other signature areas throughout the document. We are looking to simply add the signature stamp and continue to add fillable content and additional signature stamps throughout the document until it is complete to be saved.
Is there a way around this or is it a new security issue with Acrobat X causing this? Previously we were designing with Live Cycle Designer and had Acrobat 9 installed. One last thing, the sales guys will have Reader and not Pro installed on those tablet devices. Any thoughts or direction that could be provided is greatly appreciated.

I recommend that you use stamps, not signature fields. They are not the same thing.
You can add as many stamps to a document as you wish, without having to save along the way, but signatures are meant to be applied at the end, after the form is completed.
You can even design your own stamps and make them dynamic, meaning they add things like the user name and current date, etc.
Have a look at: http://www.pdfscripting.com/public/department53.cfm

Digital Signatures and APEX

Has anyone had any success implimenting digital signatures (PKI) within APEX?
Here is a brief synapsis of what we are looking to accomplish and realize that third-party hardware/software might be necessary. We require users to login using LDAP credentials. We want them to be able to generate documents (i.e. PDF, Word, or Excel) from our application data. We want the users to have the ability to Digitally Sign their documents. We will be issuing individual private keys & certificates and we are considering generating the documents as XML. We are still in requirements gathering, but wanted to explore any and all capabilities within APEX.
Any thoughts? Thanks.

Hello Francesco,
I want to generate a digital signature (PKCS#7,XML) using SAP SSF API as explained in
http://help.sap.com/saphelp_nw04/helpdata/en/4f/65c3b32107964996a56e4165077e24/content.htm and in Amol Joshi's reply in
Digital Signatures and Document Encryption api
so my question is From which PI/XI version and its SPS this SAP SSF LIBRARY is supported ?
Kind Regards,
Kubra fatima.

Digital signatures and wet ink signatures

HI all,
I am in the process of converting our paper checklists into fillable pdf forms. Everything is working well, but Im trying to get my head around digital signatures.
Ideally I just want to click the signature part, choose a user from a list, enter the password and the 'wet ink' signature that is scanned in gets added to the form.
So on my laptop I setup a new appearance for my signature, scanned my signature and added it to my digital signature. Perfect.
Problem is, I want to be able to use this on other computers. I copied the digital signature .pfx file and imported it on that new computer, which worked, but it drops the 'wet ink' signature and appearance.
It also appears that anyone can create a digital ID on my laptop and choose my wet ink signature appearance, and sign the document which makes it appear as if I have signed it. I was hoping the wet ink signature was locked with the digital signature but it appears this isnt the case.
Im trying to find the best way to store our signatures (we are all on a network), so that any user can use any computer and ideally lock the wet ink signature to the digital signature.
Many thanks
Chris

It doesn't work for everyone, but if you are considering moving to the world of digital signatures, it's best to forget the signature appearance ("wet"). This is just a distraction to the actual signature, and it encourages a deeply flawed workflow: one where people look at the picture on the page rather than learning about digital signatures and how to verify them. Since digital signatures are (if done properly) unfakeable and (in some places) legally recognised, it is best to completely change workflow, rather than trying to give the illusion it is just an electronic version of a paper workflow.

Digital Signatures and Security Policies

Is there a way to combine a digital signature and a Security Policy. We have a need to digitally sign a document, but not allow that signature to be removed and to not allow any further editing of the document?

Hello Francesco,
I want to generate a digital signature (PKCS#7,XML) using SAP SSF API as explained in
http://help.sap.com/saphelp_nw04/helpdata/en/4f/65c3b32107964996a56e4165077e24/content.htm and in Amol Joshi's reply in
Digital Signatures and Document Encryption api
so my question is From which PI/XI version and its SPS this SAP SSF LIBRARY is supported ?
Kind Regards,
Kubra fatima.

Digital Signatures and Coldfusion

I want to add a digital signature field (3 to be exact) to a PDF file that I
generate via coldfusion (via the cfdocument tag), OR use a form built in livecycle that once it is signed by the first person, the only allowable changes to the form are the second and third digital signature.
Any help would be appreciated as digital signatures are not handled in cfdocument as well (at all) as I had hoped.
Thanks,
Drew

Hello Francesco,
I want to generate a digital signature (PKCS#7,XML) using SAP SSF API as explained in
http://help.sap.com/saphelp_nw04/helpdata/en/4f/65c3b32107964996a56e4165077e24/content.htm and in Amol Joshi's reply in
Digital Signatures and Document Encryption api
so my question is From which PI/XI version and its SPS this SAP SSF LIBRARY is supported ?
Kind Regards,
Kubra fatima.

PKI- Digital signature and doc cypher

Hello everybody, I have a problem and I need help please. This is my situation:
I would like to cypher a world document and add a digital signature. I want to use certificates to do so. That is why I have developed a PKi in order to get certificates to use digital signature and ASYMMETRIC encryption. I have to add that I am trying to assure
non repudiation, integrity and confidentiality of word documents.
Is there any way to do it? if so, how can i do it and what software application do you recommend? thanks!

As Elke explains and shows via that link, that informs you how to digitally sign a document. However a digital signature only provides non-repudiation and integrity of a document, not confidentiality. Symmetric Encryption is needed for that.
You would not use Asymmetric encryption to bulk encrypt files, it would be too slow.
Unfortunately there is no easy way to symmetrically encrypt files with the tools available in modern Windows distributions. Personally I would digitally sign the document, then use a tool like 7-Zip
to encrypt them with AES-256 and a passphrase, or to go one better than that use Symantec Encryption Desktop. Using the latter allows you to do encrypt either with a passphrase, or with
your targets PGP public key (that does of course assume they are also using PGP) so that only they can decrypt it with their private half.
Also signing an Office document (or PDF for that matter) with an internal PKI certificate is only valuable if the documents are internally distributed within the same organisation, or when the other organisation(s) trust your root CA certificate, otherwise
they will not be able to verify the signature (think of it like the error in your browser with the red X stating there is a problem with your certificate).
I'm not quite sure what your use case is, but if it's just for distributing internal documents then no problem. Otherwise you'll have to get a document signing certificate from a vendor like
GlobalSign who have a trusted root certificate which ships with most operating systems so that anyone who receives the document can verify it.
D

Digital Signature and Time Stamp Settings

Would someone please tell me the location in which the Digital Signature and Time Stamp Settings from Adobe STD 10 are saved?

They are saved in the registry on Windows and in the plist on Mac. In Windows you would go into HKEY_CURRENT_USER\Software\Adobe\Adobe Acrobat\10.0\Security\ and look around there. On the Mac it in /Users/<user name>/Library/Preferences and then look for com.adobe.Acrobat.plist
Steve

Making Multiple Digital Signatures Read-only in Form (Acrobat 9)

I have created a form which includes two (2) digital signature fields. What needs to occur with the form is Person1 fills the form and then digitally signs it thereby making the form fields read-only . Person2 then digitally signs the form which should make Person1's digital signature read-only.
Here's what I've done:
1) For the Person1 digital signature field, in Digital Signature Properties, under the Signed tab, I have selected Mark as read-only <all fields except these> and selected the Person2 digital signature field.
2) For the Person2 digital signature field, in Digital Signature Properties, under the Signed tab, I have selected Mark as read-only <all fields> since once Person2 signs the form I do not want Person1 to be able to clear the digital signature and make changes to the form.
Here's what actually occurs:
Step 1 above works fine. Once the signature is applied all the form fields are read-only except for the Person2 digital signature field.
The problem is that after Person2 digitally signs the form, even though I selected all fields as read-only, Person1 can 'clear' their signature which leaves all the form fields available for editing and leaves Person2's digital signature still on the form.
I honestly don't care about 'validating' signatures on this form since it's going to be printed but I cannot allow Person2's signature to remain on the form and allow Person1 to edit the form.
--Mike.

Hi!
I have the same problem. Have not been able to figure it out, although tried everything.
Hope somebody can help
- MackeMan

Digital signatures and view document througt URL

Hello together,
We use status document and digital signatures workflow and we canu2019t use URL link to documents which have been approved. In browseru2019s window I see digital signatures information and error :u201DHTTP 404 the web page cannot be foundu201D.
In transaction SOLAR01, SOLAR02 when, I display approved document, at first I see the windows with digital signatures information and then, after push enter - required document.
If document in status u201Cin progressu201D we donu2019t have problem.
Could you help me to resolve this problem or disable windows with signatures information?

Hello Francesco,
I want to generate a digital signature (PKCS#7,XML) using SAP SSF API as explained in
http://help.sap.com/saphelp_nw04/helpdata/en/4f/65c3b32107964996a56e4165077e24/content.htm and in Amol Joshi's reply in
Digital Signatures and Document Encryption api
so my question is From which PI/XI version and its SPS this SAP SSF LIBRARY is supported ?
Kind Regards,
Kubra fatima.

Digital signatures and combining PDFs in Acrobat X

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