“Sign here…” Getting started with electronic signatures in Adobe products

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This is the latest entry in our “What is an Electronic Signature, Anyway?” series.  You can find previous entries here.

Recently, I’ve received a number of emails from our users asking questions about electronic signatures, so I thought it would be useful to briefly answer some of these frequently asked questions and also direct you, dear reader, to a variety of resources here at Adobe that can help.

First, I recommend you read the other blog entries in our “What is an Electronic Signature, Anyway? “ series to better understand the terminology and issues surrounding electronic signatures.

Now onto the questions…

I want to electronically sign a PDF—what do I need to do?

There are lots of different ways to electronically ‘sign’ documents, but they vary in terms of reliability, longer-term validity, and application.

At a very basic level, you could create a signature stamp or use the (new in Acrobat 9) ‘Apply Ink Signature’ capability to put a handwriting-like signature on the PDF that could be printed out or emailed, much in the same way a fax signature might work. These signatures don’t get you much more than that fax signature, and can be manipulated, duplicated or deleted unless the document is ‘flattened,’ but it’s one way to get started. Unfortunately, these kinds of signatures will not lock out changes or notify the recipient if something has been changed in the document…which is not so different than a wet ink signature, is it?

At a more sophisticated level, you could use a dedicated signature pad and software to capture your signature and embed it into the document. This can lock the document and notify the recipient if changes have been made. Several of our partners provide hardware and software plug-ins to manage this type of signature: CIC, Interlink, and SoftPRO.

Finally, you have digital signatures, which can lock down the document and notify recipients that the document has been changed, resulting in higher trust in the document. Acrobat provides you with the capability to create so-called ‘self-signed’ digital IDs (credentials) used to create digital signatures. While these are convenient, they do not offer the recipient any proof of the signer’s identity…the signer is vouching for his or her self. However, this may be sufficient for personal use or small-medium businesses exchanging documents in trusted relationships.

You can also purchase digital IDs from third party ‘Certificate Authorities,’ who can validate your identity and provide better assurance as to your digital signature. These digital IDs may offer other benefits too, such as automatic trust in Acrobat and Reader, and embedding of secure time & validation information (Certified Document Services). More below…


Does Adobe provide digital IDs (certificates) for use with digital signatures? If not, where do I get them?

No, Adobe does not provide digital IDs, other than giving you the ability to create self-signed ones. We rely on close partnerships with a number of leading Certificate Authorities (CAs) from around the world to provide these certificates to our customers. Certificates can be bought on a one-off basis to sign your PDF documents and email, or your organization could actually contract with these CAs for a managed service where certificates are provisioned to your users via web interfaces. Other partners sell appliances and other products that can make deploying certificates quite easy. Visit our Security Partner Community and explore the partners and solutions listed under “Digital ID infrastructure.”

Of course, your organization may already be running a PKI (public key infrastructure) in-house that can provide you with a digital ID…be sure to check with your IT department.


I’ve read about CDS…how do I join the program?

I have received a number of inquiries about Adobe’s Certified Document Services (CDS) program and see that there is some confusion about how the program works.

Note that Adobe does not sell CDS certificates per se, but rather administers the program and provides the structure by which our CDS Providers can create these higher assurance, higher trust signing credentials—in use today with the US Government Printing Office, top universities, and other organizations looking to provide assurance as to the authorship and integrity of documents of record.

So, if you are interested in taking advantage of these credentials to sign your organization’s PDF documents and experience the automatic trust provided by CDS, please contact Adobe’s CDS Providers to purchase a CDS digital ID.

However, if your organization actually operates a Certificate Authority, and you would like to learn more about how to participate in the trust programs offered by Adobe, please contact us here.


Where do I go to get more information?

That’s easy!


Posts, The Archives

Posted on 05-28-2009


  • By G. Hill - 7:05 PM on September 1, 2011  

    Question – what Adobe version (standard or pro) do I need to enable me to sign a pdf document?

    • By John B Harris - 4:23 PM on September 15, 2011  

      You can sign a PDF with either Adobe Acrobat Standard or Pro.

      • By Walter - 3:11 PM on October 7, 2011  

        Can you sign documents using self sign digital IDs, public CA using Adobe Reader? Or, do you need the full Adobe product?

        • By John B Harris - 7:29 PM on October 7, 2011  

          You can use any certificate / Digital ID for digital signatures within Adobe products. Note, however, that the limitation in Reader on signing has to do with ‘Reader-enabling’ a PDF to unlock that functionality.

          In other words, while Acrobat allows users to sign PDFs, the free Adobe Reader does not, by default. However, authors can enable/extend a PDF for signatures, form save, etc., from Adobe Acrobat Professional or the Adobe Digital Digital Enterprise Platform (ADEP, fka LiveCycle) so that users with the free Adobe Reader can use these functions.

  • By Lorrie Proal - 2:34 PM on March 14, 2012  

    Can you sign a pdf more than once? I often have 3 pages I need to sign with a digital signature but do not find a process to do this.

    • By John Landwehr - 6:50 PM on March 19, 2012  

      Yes, you can digitally sign a PDF multiple times, such as: fill -> sign1, -> sign2 or fill1 -> sign1 -> fill2 -> sign 2. You will want to read up on Modification Detection and Prevention capabilities in order to set the behavior of multiple signatures on forms.