How to check digital signature of a file

TL;DR

Checking a digital signature verifies a file's signer identity and integrity by validating the cryptographic certificate and audit trail. Use an eSignature platform like signNow to view signature metadata, verify certificate chains, check timestamps, and confirm a tamper-free document history. This process is important for legal validity, compliance with ESIGN/UETA and HIPAA where applicable, and for operational efficiency in remote workflows.

What digital signature checking is

Checking the digital signature of a file means confirming who signed it and whether the file changed after signing. Imagine a wax seal on a letter that also contains a hidden code only the sender can create; digital signature checking reads that code and confirms the seal is intact. Technically, it validates the cryptographic certificate, signer identity, timestamp, and signature integrity so the signed file remains admissible under ESIGN and UETA.

Why verifying signatures matters

Verifying a digital signature confirms authenticity, prevents tampering, and supports legal enforceability of electronic agreements. Use signNow when closing remote sales contracts or collecting employee onboarding signatures at scale. It also reduces risk for sensitive transactions and provides an audit trail acceptable under ESIGN and UETA for most U.S. business needs.

Common verification challenges

• Expired or revoked certificates can make a valid signature appear invalid even when the signer intended to sign.
• Disconnected workflows where recipients download and re-upload copies can break embedded signature metadata and invalidate checks.
• Inconsistent timezones and missing trusted timestamps may complicate evidence of when a signature was applied.
• Users unfamiliar with certificate chains can misinterpret warnings and assume a signature is fraudulent when it is not.

Who typically checks signatures

Organizations across sales, HR, legal, and healthcare routinely verify digital signatures to ensure document integrity and chain of custody.

• Real estate brokers closing leases and escrow teams validating contracts before funding.
• Healthcare administrators validating patient consent forms under HIPAA with secure audit trails.
• Legal teams confirming contract signers and timestamps for enforceability and court evidence.

Who performs checks in organizations

IT Administrator

IT administrators configure signer authentication, manage certificate trust stores, and enable platform security settings. They ensure signNow integrations, SSO, and API keys are deployed securely and that audit log retention meets organizational retention policies.

Legal Counsel

Legal teams review signature metadata and audit trails to confirm identities, signing order, and timestamps. They advise on evidentiary standards for ESIGN and UETA and work with compliance teams to document chain-of-custody for signed records.

Security and compliance facts

Encryption in transit: TLS 1.2/1.3

Encryption at rest: AES-256

Certifications available: SOC 2 Type II

Health data protection: HIPAA (BAA required)

Regulatory compliance: ESIGN and UETA

International standards: ISO 27001

Risks of skipping verification

Invalid agreements: Contracts deemed unenforceable

Compliance fines: Regulatory penalties possible

Data breaches: Unauthorized access risk

Reputational damage: Loss of client trust

Financial loss: Fraud or payment disputes

Operational delays: Slower closing times

Real-world verification examples

These brief examples show how organizations use signNow to check digital signatures and keep file integrity intact.

Optica Ventures (COO)

Optica adopted signNow to eliminate mail and in-person signings

• The team used templates and remote signer authentication
• Signatures and audit trails sped contract execution

Resulting in faster customer acceptance and fewer signature-related disputes.

Xerox (NetSuite Director)

Xerox integrated signNow with NetSuite to automate sales approvals

• Embedded signature metadata verified signer identity and timestamp
• The integration preserved certificate details within each transaction record

Leading to clearer audit records and faster reconciliations between legal and finance teams.

Step-by-step check and verification

Follow these clear steps to check a file's digital signature using an eSignature workflow in signNow.

• 01
  Upload Document: Sign in to signNow, click Upload, and choose the signed file from your computer.
• 02
  Open Audit Details: In the document view, select the Audit Trail or Signature Details button to reveal metadata.
• 03
  Verify Certificate: Inspect certificate issuer, expiration, and revocation status shown in the signature metadata panel.
• 04
  Confirm Integrity: Check the integrity flag or tamper-evidence message to ensure the document has not been altered.

How verification works in workflows

Digital signature verification follows a predictable flow: capture, certify, store, and validate. signNow surfaces these steps in the UI and audit logs for easy review.

• Capture: Document is signed and certificate embedded.
• Timestamp: Trusted timestamp recorded with signature.
• Store: Signed file saved with audit trail.
• Validate: Viewer checks certificate chain and integrity.

Key features that aid checking

Several signNow features make checking digital signatures straightforward: embedded audit trails, signer authentication, certificate details, and tamper-evidence indicators.

Audit Trails

Comprehensive, time-stamped logs show actions for each signer, IP addresses, and timestamps so reviewers can trace who did what and when during the signing process.

Signer Authentication

Options include email, SMS, and advanced authentication to confirm signer identity before signature, reducing the risk of impersonation in high-value or regulated transactions.

Certificate Details

Signature metadata reveals certificate issuer, serial number, and validity period so an examiner can validate chain of trust and detect revoked or expired certificates.

Tamper Evidence

Files show a tamper indicator or integrity flag when opened; any post-signing changes break the cryptographic signature and are clearly identified for reviewers.

Best practices for signature checks

Follow these operational and technical practices to reduce risk and make signature verification consistent across teams.

Standardize verification procedures across teams

Create a documented checklist for reviewing signature metadata, certificate validity, and audit trail entries. Train legal, HR, and finance teams to use the same checklist so verification is uniform and defensible during audits.

Require signer authentication for sensitive documents

Use multi-factor signer authentication and identity-proofing for contracts involving finance, healthcare data, or high-value transactions. This reduces impersonation risk and strengthens admissibility under ESIGN and sector regulations.

Preserve original signed files and audit trails

Store signed documents and their audit logs in secure cloud storage with restricted access, retention rules, and backup to maintain evidentiary records for compliance and legal reviews.

Automate checks in frequent workflows

For repeatable use cases like HR onboarding or sales contracts, embed automated verification steps in signNow workflows and templates to ensure signatures are always validated consistently.

Where and how to verify

You can check digital signatures on web browsers, mobile apps, and via API integrations that surface signature metadata and audit trails.

• Web Browser: Desktop supported
• Mobile App: iOS and Android
• API Access: Available via REST

Using signNow's web app or mobile apps lets reviewers view signature details and audit trails immediately; APIs allow automated validation in backend systems and integrations with document repositories.

Typical verification workflow settings

These configuration examples reflect common defaults for checking digital signatures in an enterprise signNow deployment.

Setting Name	Default Configuration
Reminder Frequency	48 hours
Authentication Method	Email + SMS
Audit Trail Enabled	Enabled
Storage Location	Secure cloud
Signature Expiration	30 days

Pricing and feature comparison (May 2026)

Pricing and feature indicators below summarize common considerations as of May 2026; check vendor sites for plan-level specifics and regional variations.

	signNow	DocuSign ($8 ser/mo)	Adobe Sign ($13/user/mo)	PandaDoc ($19/user/mo)	HelloSign ($15/user/mo)
Starting Price	$8/user/mo	$8/user/mo	$13/user/mo	$19/user/mo	$15/user/mo
Free Trial	7-day free trial	Varies by plan	Varies by plan	Varies by plan	Varies by plan
Bulk Send	Yes, on Business Premium	Varies by plan	Varies by plan	Yes, on some plans	Varies by plan
Audit Trail	Yes, full audit trail	Yes	Yes	Yes	Yes
HIPAA Compliant	Yes, BAA required	Varies by plan	Varies by plan	Varies by plan	Varies by plan
Envelope Cap	No envelope cap	100 envelopes/user/year	Varies by plan	Varies by plan	Varies by plan