How do I add a digital signature to my PDF change log?

Open your PDF in Acrobat. Go to 'Tools' > 'Certificates'. Click 'Sign Digitally' or 'Certify' and follow the prompts to select your Digital ID. Place your signature on the document and save it.

What is the difference between 'Certify' and other digital signatures in Acrobat?

Certifying a PDF is a special type of digital signature. It can only be the very first signature on a document. When you certify a PDF, you are stating that the content is final and approved, and it locks the document from further changes that would invalidate the certification. Other digital signatures can be added to a document that already has content, and they might allow for more changes after signing.

Why would I want to certify my change log PDF?

Certifying your change log PDF provides a high level of trust and integrity. It proves that the document has not been altered since you certified it, which is crucial for official records, audit trails, or legal documents. It acts as an official seal, giving recipients confidence in the document's authenticity and completeness.

What is a Digital ID and why is it important for certifying PDFs?

A Digital ID is a file on your computer or a hardware token that contains your unique private key and public certificate. The private key is used to create your digital signature, and the public certificate allows others to verify that the signature is truly yours and that the document hasn't been changed. It's important for certifying PDFs because it links your identity to the document, ensuring non-repudiation and document integrity.

If my change log PDF already has a simple digital signature, can I still certify it?

No, you cannot certify a PDF if it already has any other type of digital signature. The 'Certify' feature in Acrobat is designed to be the very first and only signature on a document. If your change log is already signed, you would need to revert to an unsigned version to use the certification feature.

◆ Acrobat · sign

Digitally sign PDFs with hardware tokens or smart cards

Certify and timestamp change logs as PDFs and manage the agreements so auditors can verify approvals and reduce compli…

3ready prompts

1real task

3roles

See the prompt↓More sign workflows

When to use it

real situations

You need to sign a contract for a new job online.
Your school asks you to sign a permission slip digitally.
A bank requests your digital signature on a loan document.

AI prompts

3 ways to ask · copy any one

AExecute — “help me do it”Please guide me to digitally sign my PDF using my hardware token…+

Please guide me step-by-step to digitally sign my PDF using my [hardware token or smart card] in Adobe Acrobat.

when the reply comes backWould you like tips on keeping your digital signature safe?

BImprove — “do it better”How can I make my digital signature stronger and safer when signing…+

How can I make my digital signature stronger and safer when signing PDFs with my [hardware token or smart card]?

when the reply comes backNeed help setting up your hardware token or smart card?

CDecide — “help me choose”Should I use a hardware token or a smart card for signing…+

Should I use a hardware token or a smart card for digitally signing my PDF in Adobe Acrobat, and why?

when the reply comes backWant to learn how to check if your signature is valid?

How to do it

the tool · the steps · what to avoid

1
Open the PDF file you want to sign in Adobe Acrobat.
2
Go to the toolbar and select Tools.
3
In the Tools center, find and select Certify and Sign.
4
In the toolbar, click Sign.
5
Use your cursor to draw the area in the document where you want the signature to appear.
6
In the dialog that appears, select your digital ID from the list and click Continue.
7
If prompted, enter your digital ID password and click Sign.
8
Choose a location to save the newly signed PDF, enter a filename, and click Save.

In the appWith the API

You can preview how your signature will look before you finalize and save the signed document.

This runs in the Acrobat app - there is no separate API for this task.

Glossary

words on this page

PDFA common file type used to share documents that look the same everywhere.ExampleShe saved the brochure as a PDF so everyone would see the exact same layout and fonts.

Digital signatureA digital signature is an electronic mark that proves who signed a document and that it has not changed.

Hardware tokenA hardware token is a small device or card you use to prove your identity online.ExampleYou plug a small USB device into your computer to log into your secure work account.

Who does this

3 roles

Contract ManagerLegal CounselProcurement Specialist

FAQ

about this task

To digitally sign a PDF in Adobe Acrobat with a hardware token, you need to connect your token or smart card to your computer, open the PDF in Acrobat, and choose the option to sign it. Acrobat will ask you to use your token or smart card to add your digital signature. This helps prove the document is really from you.

A digital signature uses special technology, like a hardware token or smart card, to prove your identity and protect the document. A regular electronic signature can be just a typed name or image, but it is not as secure or trusted as a digital signature.

Organizations require hardware tokens or smart cards because they make digital signatures much more secure. These devices store your private information safely, so only you can use them to sign documents, which helps prevent fraud.

You can use a hardware token or smart card to sign most PDFs, but the computer and Adobe Acrobat must support your device. Some older PDFs or software versions may not work well, so it's best to check compatibility first.

If Acrobat does not recognize your device, make sure it is connected properly and the necessary drivers or software are installed. Restarting your computer or updating Acrobat may also help. If problems continue, contact your IT support or the device provider.