Trusted Signatures

Most document fraud is simple: someone edits a PDF after it leaves your system. Trusted Signatures prevents that by sealing each file with a cryptographic signature and an optional TSA timestamp. If the file changes—even by one pixel—the seal breaks and verification fails.

How it works

1. Your system generates a PDF and sends it to our CLI, API, or Zap. We send a digest (never your PDF) to our server.

2. We sign in hardware (HSM) and return a detached CMS/PKCS#7.

3. You attach the seal to the PDF; it verifies in Acrobat and our web validator.

4. Recipients can check authenticity without installing anything.

What you can do

• Seal outgoing invoices so AP teams know they’re safe to pay.

• Require sealed bids and verify they weren’t opened or changed.

• Timestamp compliance reports so audit teams see when they were finalized.

• Embed verification in your product to stop “fake PDFs” at the edge.

What it isn’t

• Not a DocuSign competitor. No multi-party signature routing or approvals—just strong sealing and verification.

Key features

• Adobe-trusted seals (AATL/EUTL chain)

• RFC 3161 TSA timestamping (optional)

• API + CLI; accepts SHA-256 digest, returns detached CMS (PKCS#7)

• Policy checks (DocMDP/permissions) and chain-of-custody metadata

• Web validator for recipients; works offline in Adobe Acrobat

• HSM-backed keys (AWS) with per-customer options

• Works with PDF 1.x and 2.0; supports PAdES-style detached signatures

Who it’s for
Accounts Payable, Compliance/Risk, Government procurement, and SaaS teams that need document authenticity without building an e-signature product.

Use cases

• AP invoice sealing and inbound verification

• Sealed bids and tenders (verify open time with timestamps)

• Sealed compliance reports / attestations

• Vendor documents (licenses, certificates, statements of work)