How do I know if a digital signature in my document is valid?

Open your PDF document in Adobe Acrobat. Click on the 'Signatures' panel on the left side. Right-click on the specific digital signature you want to check. Select 'Validate Signature' from the menu to see its status.

What is a trusted identity and why does it matter for digital signatures?

A trusted identity refers to a digital certificate that you have chosen to trust in Adobe Acrobat. It matters because Acrobat uses this trust to decide if a digital signature is valid. If you trust the certificate of the person who signed the document, Acrobat can confirm their identity and that the document has not been changed since they signed it. Managing trusted identities helps you control who you believe is authentic.

If a digital signature says 'valid but with warnings', what should I do?

First, check the warning details. It might be about the certificate's trust or a timestamp issue. Next, try to verify the certificate information. Make sure it comes from a known and reliable source. Consider adding the signer's certificate to your list of trusted identities if you know and trust them. If the warning is about long-term validity, add LTV information to make the signature self-validating over time.

Why is it important to add Long Term Validation (LTV) information to a digital signature?

Adding Long Term Validation (LTV) information to a digital signature is important because it helps the signature stay valid far into the future. Without LTV, a signature might become invalid if the signer's certificate expires or is revoked. LTV embeds all the necessary information, like timestamps and revocation status, directly into the PDF, making the signature self-validating over a long period, even without external checks.

What is the difference between verifying a signature and managing trusted identities?

Action Purpose Outcome. Verifying a signature To check if a specific digital signature on a document is valid, who signed it, and if its certificate is trusted at that moment. You get an immediate status report on the signature's validity and integrity. Managing trusted identities To tell Adobe Acrobat which digital certificates you personally trust, so it can use this information for future signature validations. You build a list of trusted signers, making future signature verifications smoother and more reliable based on your preferences.

Validate signatures with timestamp verification in Adobe Acrobat — How-to & AI prompts

AI prompts

3 ways to ask · copy any one

AExecute — “help me do it”Check if the signature and timestamp on [document] are valid...…+

Check if the signature and timestamp on [document] are valid and show me the details.

when the reply comes backWant to learn how to add your own digital signature?

BImprove — “do it better”Make the timestamp verification easier to understand for someone new...…+

Make the timestamp verification easier to understand for someone new to Adobe Acrobat.

when the reply comes backNeed tips on spotting fake or changed timestamps?

CDecide — “help me choose”Should I use Adobe Acrobat or another tool to check...…+

Should I use Adobe Acrobat or another tool to check signatures and timestamps for [my purpose]?

when the reply comes backCurious about how timestamps help keep documents secure?

How to do it

the tool · the steps · what to avoid

1
Open the PDF document containing the digital signature you want to validate.
2
Locate the signature field or signature panel in the document.
3
Click directly on the digital signature or open the signature panel and select the signature you wish to validate.
4
In the signature details popup, click Signature Properties.
5
In the Signature Properties dialog, click Show Certificate to review certificate details if needed.
6
Close the certificate window, then click Validate Signature in the Signature Properties dialog.
Best practiceIf the signature status shows as 'Unknown' or 'Not Valid', check if the signer's certificate needs to be added to your list of trusted identities.
7
Review the validation result displayed in the Signature Properties dialog.

In the appWith the API

You can view detailed information about the signature's validity and certificate by clicking on the signature and opening Signature Properties.

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

Glossary

words on this page

SignatureYour name written in a special way to show you agree or approve.ExampleHer distinctive signature on the artwork proved its authenticity and origin.

TimestampA timestamp proves exactly when a document was signed.ExampleThe timestamp on the digital signature shows the agreement was finalized at 2:15 PM.

ValidateTo check if something is real or correct.ExampleThe system validates your login details to confirm you are an authorized user.

The real tasks

the one, listed here

Finance asked for an audit trail today and I need to confirm every agreement has auditable timestamps.

FAQ

about this task

In Adobe Acrobat, you can open the document and click on the signature to see details. Acrobat will show if the signature is valid and display the exact date and time it was signed. This helps you know if the document is real and when it was approved.

Verifying a signature's timestamp means checking both that the signature is real and that the date and time recorded are correct. This is important for making sure the document hasn't been changed after it was signed.

Timestamp verification is important because it proves when a document was signed. This can help solve arguments about who signed first or if the document was changed later.

Not always. Some signatures or timestamps may be fake or changed. Adobe Acrobat can help you check if they are valid, but you should also make sure the document came from a trusted source.

Adobe Acrobat checks the digital code behind the signature, not just the picture. This means it can tell if the signature is real and if the document has been changed, while just looking at an image cannot.

Validate signatures with timestamp verification

When to use it

AI prompts

How to do it

Glossary

The real tasks

Who does this

FAQ

Sources

Adobe help