How do I know if a digital signature is truly valid?

Open the PDF document with the signature. Right-click on the digital signature in the document. Select 'Validate Signature' from the menu that appears. Acrobat will show you the validation status. It checks if the signature is real and if you trust the signer.

If my document's digital signature shows 'unknown validity,' what should I do?

First, check the signer's certificate. Right-click the signature and choose 'Show Signer's Certificate'. Next, try to add the signer's certificate to your list of trusted identities in Acrobat. This often resolves 'unknown validity' issues. If it's still unknown, contact the sender to confirm their signing method and certificate.

What is the difference between a digital signature and a simple electronic signature?

Feature Digital Signature Electronic Signature. Security Uses cryptography and certificates for high security. Can be as simple as typing your name or a scanned image. Verification Includes data to verify signer identity and document integrity. Verification methods vary, often less robust. Trust Relies on a trusted certificate authority. Trust depends on the agreement between parties.

Trust-Building Approvals in Adobe Acrobat — How-to & AI prompts

AI prompts

1 way to ask · copy any one

DBecome — “help me grow”After running bulk approvals for six weeks, small but important errors slipped through. Help me…+

After running bulk approvals for six weeks, small but important errors slipped through. Help me redesign the approval matrix so high-volume items move fast but investigative or legally sensitive pieces still get thorough review. Propose one change to role responsibilities and one measurable gate that preserves speed without increasing risk.

when the reply comes backPush once: ask it to sharpen the weakest part, and to say what it assumed.

How to do it

the tool · the steps · what to avoid

1
Open the signed PDF document in Adobe Acrobat.
2
Open the Signatures panel from the navigation pane.
3
Right-click the signature you want to validate and select Validate Signature.
4
In the signature validation status dialog, review the signature details and validation status.
5
Click Show Certificate to review certificate details and ensure it matches the required legal or industry standard (e.g., eIDAS, FDA 21 CFR Part 11).
CautionYou must know your organization's required certificate authorities and validation criteria for compliance.
6
Review the signature properties panel for compliance details specific to regulatory standards.
NoteThis option appears only if the signature contains compliance information.
7
Check the validation summary for explicit compliance statements or error messages regarding legal or industry standards.
8
If the signature is not compliant, consult your organization's digital signature policy or contact your certificate provider for remediation.
Best practiceSome enterprise workflows require importing trusted root certificates into Acrobat's trusted identities list to validate signatures against specific regulations.

In the appWith the API

You can configure trusted identities in Acrobat to ensure signatures are validated against your organization's compliance requirements.

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

Glossary

words on this page

Digital SignatureAn electronic mark on a document that proves who signed it and that the document has not changed.ExampleA digital signature on your tax return confirms you submitted it and that its contents are unchanged.

CertificateAn electronic file that proves a person's or organization's identity online, like a digital ID card.ExampleYour certificate confirms your identity when you access secure online government services.

Trusted IdentitySomeone whose digital signature certificate you have chosen to trust in your software.ExampleYou add your manager's digital signature certificate as a trusted identity in your document software.

The real tasks

the one, listed here

I want smarter approvals so sign-off builds trust instead of eroding it.

FAQ

about this task

Open the PDF document with the signature.
Right-click on the digital signature in the document.
Select 'Validate Signature' from the menu that appears.
Acrobat will show you the validation status. It checks if the signature is real and if you trust the signer.

A digital signature is only as strong as the trust you place in the signer's certificate and the timestamp server. If you don't trust the certificate, Acrobat cannot confirm the signer's identity. This trust relationship is key to knowing if the signature is authentic and hasn't been tampered with since it was signed. You manage these trusted relationships in Acrobat to ensure security.

First, check the signer's certificate. Right-click the signature and choose 'Show Signer's Certificate'.
Next, try to add the signer's certificate to your list of trusted identities in Acrobat. This often resolves 'unknown validity' issues.
If it's still unknown, contact the sender to confirm their signing method and certificate.

Feature	Digital Signature	Electronic Signature
Security	Uses cryptography and certificates for high security.	Can be as simple as typing your name or a scanned image.
Verification	Includes data to verify signer identity and document integrity.	Verification methods vary, often less robust.
Trust	Relies on a trusted certificate authority.	Trust depends on the agreement between parties.

Adding verification information, known as Long-Term Validation (LTV), is crucial because the validity of a digital signature can change over time. Certificates expire, or their issuing authority might become untrusted. LTV embeds all the necessary validation data, like timestamps and revocation status, directly into the signed document. This makes the signature self-validating, ensuring it remains verifiable even if external sources (like certificate servers) are no longer available or the original certificate has expired. It's vital for documents that need to be legally valid for many years.

Trust-Building Approvals

When to use it

AI prompts

How to do it

Glossary

The real tasks

Who does this

FAQ

Sources

Adobe help