How PDF Digital Signatures Prove Authenticity

When a PDF is sealed with a digital signature, it gets a unique fingerprint. From that moment on, any change — even a single word — will break the seal and be detected.

Finance & Operations: Embed sealing into your existing processes to eliminate manual handoffs, reduce operational overhead, and cut data-transfer costs.
Security & Compliance: Maintain airtight data privacy and auditability by keeping documents on-premises; avoid third-party exposure and streamline regulatory reviews.
Product & Developers: Rapidly integrate a single /sign API or CLI command into your apps—no external dependencies, no session state, and no complex routing.

Adobe Acrobat verifies this automatically and shows a blue certified banner when the document is authentic and unchanged. This gives your agreements, reports, and records legal standing and protects your organization against tampering and fraud. Learn more about our security features and implementation options.

How PDF Sealing Works

(Click any step to learn more)

Step 1: Create a unique fingerprint

Your PDF gets a unique digital fingerprint. If even one word changes, the fingerprint changes.

Step 2: Lock with your certified seal

We lock that fingerprint with a certified seal tied to your business identity and embed the seal into your document. Any change breaks the seal.

Step 3: Distribute

Your document can now safely be distributed without worry that it will be tampered.

Later, when anyone opens your document:

Step 1: Acrobat verifies the embedded seal

Acrobat confirms that the seal comes from your business.

Step 2: It compares the sealed fingerprint to the document data

Only an authentic PDF will have a fingerprint that matches the one in its seal.

Step 3: If the it’s a match, the document is authentic

The PDF is unmodified since it was sealed
It came from the indicated signer
Nothing has changed since it was sealed
Acrobat displays this at the top of the PDF:

If the fingerprints don’t match, it’s been modified

The PDF is tampered
The document cannot be trusted
Acrobat displays this at the top of the PDF:

Defensible Documents - Every Time

The simplest, most affordable way to prevent document fraud—dramatically cheaper than building yourself or doing nothing.

Trust: No one can alter invoices or contracts without detection.
Pass audits: Regulators see Adobe’s Certified banner instantly.
Protect your reputation: Clients know your documents are authentic.

Publisher - Trusted PDF Sealing offers a one-step, run-and-done service that handles cryptography, certificate lifecycle, and PDF manipulation so teams can secure files without PKI complexity.

Ready to get started? Try our CLI tool, explore our API, or set up Zapier automation. Check our pricing or browse our Identity FAQ for common questions.

Learn more about our security features and easy-to-use tools.

Digital Trust for Business Documents