Security at SignMaster
Every signature, sealed.
SignMaster fingerprints every document, keeps a log of every step that no one can rewrite, and walls each company's contracts off from everyone else's.
Tamper-evident by design
How a signature stays a signature.
Four layers of evidence travel with every envelope, so anyone can tell if a signed document was changed.
Fingerprint every original
When you send, SignMaster records a SHA-256 fingerprint of each original file. Before the final PDF is built, every file is checked against it, and a mismatch stops the process.
Log every step, permanently
Sent, viewed, signed, declined: each event records the time in UTC, who did it and their IP address. The database refuses to edit or delete these events, even for SignMaster's own server account.
Seal it into one PDF
When the last person signs, their entries are flattened into the pages, the envelope ID is printed on every page, and a certificate of completion is attached with each signer's consent, IP address and device.
Fingerprint the result
The finished PDF gets its own SHA-256 fingerprint, saved with the envelope. Sent envelopes can't be deleted one by one, so their evidence stays with your records.
Protections, built in.
On every plan, with nothing to switch on.
Encrypted in transit and at rest
Every connection uses HTTPS. Our database and file storage provider encrypts customer data at rest with AES-256.
Walled-off workspaces
Row-level security is switched on for every table in our database, so each company's records are visible only to its own team.
Roles and permissions
Owner, Admin, Member and Viewer, or roles you build yourself. Limit people to the envelopes they created or were added to.
Private signing links
Each link carries 256 bits of randomness and we store only a hash of it. A signer sees their own fields, never a co-signer's.
Access codes for signers
Ask for a code, or a one-time code sent by email, before a signer sees anything. Five wrong tries locks the link for a while.
Rate limits on public pages
Signing pages, access codes, public signing links and phone-scan links are rate limited to slow down guessing.
Private file storage
Documents, signatures and signer uploads sit in private storage, filed under each company and served only to people allowed to see them.
App lock on iPhone and iPad
Lock the app with Face ID, Touch ID or a PIN. Leaving in-person signing mode takes your Face ID or passcode.
In-person signing, safely
A homeowner signing on your device can't use your saved signature, and the certificate records who hosted the signing.
Payments by Stripe and Apple
Subscriptions are paid through Stripe on the web and Apple in the app. We never see or store your card number.
API keys stored as hashes
API keys and connect codes are kept only as hashes, and each key carries just the permissions you gave it.
Browser protections
Other sites can't frame SignMaster pages unless a workspace approves that site for embedded signing, and signing links are never passed along in the Referer header.
What we never do.
- Sell your dataWe don't sell personal information, and we don't use your documents for advertising.
- Train AI on your documentsYour documents and signer data aren't used to train AI models, by us or by our AI provider.
- Let Alana sign or sendAlana prepares drafts. Sending is always your call, and anything she changes waits for you to confirm.
- Store card numbersStripe and Apple handle payment details. SignMaster only learns which plan you're on.
- Keep raw links or codesSigning links and access codes are stored as hashes, so a database copy can't open anyone's envelope.
- Make signers sign upHomeowners sign from a private link on any phone or computer. No account, no app to download.
Legally sound
Built for the ESIGN Act and UETA.
The U.S. laws that make electronic signatures as binding as ink, and the evidence each signature needs to hold up.
Consent before signing
Every signer agrees to sign electronically first. Their consent, and the version of the disclosure they saw, are recorded.
Disclosure in English and Spanish
The consumer e-signature disclosure is published in both languages, and signers can switch anytime.
Read the disclosure ›Certificate on every document
Each completed PDF carries a certificate of completion and the full timestamped event history.
Your privacy rights
Depending on where you live, you can ask to access, correct, delete or export your personal information.
Read the Privacy Policy ›Your data, your call.
Take it with you
Download any completed PDF with its certificate, and export what signers entered on an envelope as a CSV.
Delete your account
Delete it in the app or in Settings on the web. We delete it 7 days after you ask, and you can cancel until then.
What we keep, and for how long
Documents and audit trails stay while your workspace exists. If a workspace is deleted, we keep only the signed copy of each completed document and its certificate, securely, for 7 years after signing as evidence of the agreement, then delete them.
Found a security issue?
Email us what you found and how to reproduce it. Please give us a reasonable chance to fix it before telling anyone else, and don't access or change other people's data while you test.
Email the security teamsecurity@usesignmaster.app
Please don't include anyone's personal data in your report.