A PAdES digital signature
The sealed PDF is signed to the European PAdES standard, the format PDF readers already know how to verify. Change one character and the seal breaks.
Electronic signatures, sealed
Signatures that hold up.
sigillumSign sends your documents for signature, confirms who is signing, and seals the finished PDF. Years from now, anyone can check who signed, when, and that nothing has changed since.
Who it is for
For any business whose signatures need to hold up
Leases, engagement letters, loan paperwork, offer letters, consent forms. When one of them is questioned, an email trail and a scribble are not much to stand on. sigillumSign gives every signed document a record you can hand over: what was signed, by whom, how they were identified, and when.
It works the same for a two-person firm and for a regulated one. Healthcare teams get a HIPAA-ready service on every plan; everyone gets the same evidence.
How it works
Prepare. Verify. Sign. Seal.
One pass from a PDF to a sealed record, started by your software or by your staff.
-
Prepare
Your system sends a PDF, its fields and its recipients in one API call, or starts from a template your team already approved. You get an envelope back.
POST /api/v1/envelopes -
Verify
Each signer gets a private, single-purpose link that expires on schedule, then confirms a one-time code sent by email or text. No account, no password, no app.
recipient.verified -
Sign
The signer agrees to sign electronically before anything else happens, then reviews the document and signs in the browser on any phone or computer.
recipient.consent_given -
Seal
The finished PDF is sealed with a digital signature, stamped with a trusted time, and returned with its certificate of completion. Your system hears about it through a signed webhook.
envelope.sealed
Evidence
The audit trail is the product
Most signing tools treat the audit log as an appendix. sigillumSign is built the other way around. Every step, from the envelope being created to the identity check, the consent, each signature and the seal, is written once, in order, and never edited or deleted.
Every completed envelope comes back as two documents:
- The sealed PDF. It carries its own proof, so any standard PDF reader can show that it has not changed since it was sealed.
- A certificate of completion. Who signed, how each person was identified, what they agreed to, and when, in plain language.
So when someone asks who signed this, when, and how do you know, you hand them a certificate instead of searching an inbox.
| Time | Event | Detail |
|---|---|---|
| 14:02:11Z | envelope.created | via API |
| 14:02:12Z | envelope.sent | 1 recipient |
| 14:29:31Z | recipient.otp_sent | |
| 14:29:47Z | recipient.verified | one-time code |
| 14:30:02Z | recipient.consent_given | disclosure v1 |
| 14:31:40Z | recipient.signed | page 4 |
| 14:32:08Z | envelope.sealed | Sealed |
The seal
Built to be checked later, not just today
A signature is only as good as your ability to prove it in five years. Each seal is made from open standards, so checking it never depends on us.
A trusted timestamp
An outside timestamp authority countersigns the moment of sealing under RFC 3161, so the time does not rest on our clock.
Long-term validation
The certificate status and timestamp material needed to check the seal are embedded in the file and kept fresh, so it can still be verified years later, offline.
A key that stays in hardware
The sealing key was created inside a hardware security module in Azure Key Vault Premium and never leaves it. Our code only ever sends a fingerprint of the document to be signed.
Developers and staff
An API for your systems. A portal for your people.
Everything sigillumSign does is an API call. Your system opens an envelope, your signer signs on their phone, and your system hears back through a webhook signed with a key you hold, so it can confirm the message came from us before acting on it.
When a person needs to take over, the portal puts envelopes, templates, delivery status and the audit trail in one place, with no engineer required. Use the API, the portal, or both.
# open an envelope from a template
POST /api/v1/envelopes
{ "template": "tmpl_engagement_letter",
"recipients": [{ "name": "…", "email": "…" }] }
201 { "id": "env_8kq2…", "status": "sent" }
# the signer verifies, consents, and signs
webhook envelope.sealed
sealed.pdf · certificate.pdf
signature verifiedSecurity and compliance
Security is the foundation, not a tier
Every plan gets the same protections. There is no premium tier for doing it properly.
Verified signers
Single-purpose links that expire, one-time codes by email or text, and signer sessions held in secure cookies, never in browser storage.
Consent on the record
Agreement to sign electronically and the intent to sign are captured as steps in the signing, in line with the US ESIGN Act, rather than assumed.
HIPAA-ready
Documents and signer details are encrypted in transit and at rest, access is controlled, and their contents are kept out of logs. Health information is handled as health information.
Records that cannot be rewritten
Audit events are append-only and sealed documents are kept in storage that cannot be overwritten. Evidence is added to, never edited.
Next step
See sigillumSign seal a document
A short walkthrough: prepare, verify, sign, seal, and the certificate at the end. Bring your most complicated packet, and your document volume, and we will walk you through pricing.