How to validate digital signatures in PDFs using eMudhra: A complete guide.

Yes, but scanned PDFs are image-based and do not retain digital signature metadata. To validate a digital signature:

• Ensure the PDF was signed digitally, not just a scanned version of a physically signed document.
• Use Optical Character Recognition (OCR) in Adobe Acrobat to extract text before verifying authenticity.
• If a scanned document requires a legally recognised digital signature, ask the sender to sign it electronically using Adobe Acrobat.

Tip: If a signature appears as an image, it is not a true digital signature and cannot be validated.

A revoked digital signature means the issuing Certifying Authority (CA) has declared it invalid. To check:

• Open the PDF in Adobe Acrobat and click the signature panel.
• Look for a message stating "This signature has been revoked."
• Cross-check with eMudhra’s certificate revocation list (CRL) to confirm the signature’s status.
• Contact the signer or issuing CA if you suspect an issue.

Tip: A revoked signature means the document is no longer valid for legal or business transactions.

Yes, if you handle multiple signed documents, you can bulk-verify digital signatures in Adobe Acrobat:

• Open Adobe Acrobat Pro and navigate to Batch Processing.
• Select multiple PDFs and apply the "Validate Signatures" tool.
• Acrobat will scan all files and generate a verification report.

Tip: Bulk validation is useful for legal, banking, or corporate documents that require auditing.

If a document is altered after signing, the digital signature becomes invalid.

• Adobe Acrobat will display a warning: "This document has been modified after signing."
• Tampering detection is built into digital signatures to ensure document integrity.
• If an update is necessary, request the original signer to re-sign the document.

Tip: To protect against accidental modifications, enable "Read-Only" mode in Adobe Acrobat after signing.

Yes, digital signatures are linked to Digital Signature Certificates (DSCs), which have expiry dates (typically 1–3 years).

• When a DSC expires, documents signed with it remain valid, but new signatures require certificate renewal.
• To check a signature’s expiry:
• Open Adobe Acrobat, go to Signature Properties, and check the validity period.
• Renew your eMudhra DSC before expiry to ensure seamless document signing.

Tip: Set reminders for DSC renewals to avoid issues with signing new documents.

Yes, but the acceptance of digital signatures varies by country.

• India: Governed by the IT Act, 2000, and eMudhra’s digital signatures are legally recognised.
• United States & EU: Recognise digital signatures under eIDAS (EU) and the ESIGN Act (US).
• Some countries require specific Certifying Authorities (CAs) for international recognition.

Tip: If signing cross-border contracts, ensure the recipient country recognises your CA’s digital certificate.

If you change computers, you must transfer your Digital Signature Certificate (DSC):

• Export your DSC file (.pfx or .p12 format) from your old computer.
• Import it into Adobe Acrobat on your new device under "Digital IDs" > "Add Digital ID."
• Ensure you update the certificate password to maintain security.

Tip: Backup your DSC to a secure USB or cloud storage to prevent data loss.

Though often confused, digital signatures and e-signatures are different:

Digital signature features:

• Uses encryption and certificates for security.
• Legally validated by Certifying Authorities (CAs).
• Suitable for contracts, banking, and tax filings.

E-signature features:

• Provides basic electronic approval.
• No formal identity verification required.
• Commonly used for internal approvals and agreements.

Tip: Use digital signatures for legal compliance and e-signatures for general business approvals.

Yes, but you need a compatible mobile app.

• Adobe Acrobat Mobile allows viewing and verifying digital signatures.
• eMudhra’s mobile application lets you sign and manage DSCs.
• Some transactions may still require desktop access for advanced signing.

Tip: Use Adobe Acrobat's cloud-based services to access signed documents from anywhere.

If Adobe Acrobat does not recognise your digital signature:

• Check if eMudhra’s root certificate is installed under "Trust Manager" > "Certificates."
• Ensure your DSC is valid and has not expired.
• Manually add eMudhra’s CA certificate by importing it from eMudhra’s official website.
• Contact eMudhra support if issues persist.

Tip: Keeping your Adobe Acrobat and security certificates updated prevents validation issues.