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How SignNada works

1

Upload and share

Upload a PDF, add your signers, and share the signing link. No accounts needed — just an email address for each signer.

2

Everyone signs

Each signer reviews the document, verifies their email with a one-time code, and signs with a cryptographic key generated in their browser.

3

Download and verify

Once everyone has signed, every participant receives the completed PDF. The signed document is self-contained — anyone can verify it at any time.

Why professionals use SignNada

Self-contained PDF

The signed document carries a ChromaCode stamp containing every signature, every public key, and the full cryptographic record. Nothing else is needed to verify it.

Ephemeral by design

Your document is encrypted on our server only during the signing window. After completion or expiry, all server data is permanently deleted.

Signer-held keys

Each signer generates their own signing key in their browser. The private key never leaves the device. The server never signs on behalf of anyone.

Mandatory review

Every signer must scroll through the entire document before signing. This is recorded in the cryptographic record and covered by their signature.

Questions

SECURITY AND PRIVACY

How is my document protected during signing?
Your document is encrypted with a unique key the moment it is uploaded. It remains encrypted on the server for the duration of the signing window. Only signers with the signing link can view it.
What happens to my data after signing?
All server-side data is permanently deleted — the encrypted document, metadata, and encryption keys. The only remaining copy is the signed PDF sent to participants.
Who can see my document?
Only people with the signing link. There are no accounts, no dashboards, and no stored documents. The sender distributes the link directly to signers.

SIGNING

What does "sign" mean here, technically?
Each signer generates an ECDSA P-256 key pair in their browser. The private key signs a hash of the document along with the signer's verified email and review timestamp. The server adds a countersignature as witness.
Do I need to create an account?
No. SignNada does not have accounts, passwords, or profiles. You verify your email with a one-time code each time you send or sign a document.
What if a signer does not sign?
The signing link expires after 72 hours. If not everyone has signed by then, the package expires and all data is deleted. The sender can create a new signing request at any time.

VERIFICATION

How does verification work?
Every signed PDF carries a ChromaCode stamp — an open-source data format we built that encodes the full cryptographic record into a single image. Verification decodes the stamp, checks each signature against its public key, and recalculates the document hash to confirm nothing was modified.
Can I verify a document years from now?
Yes. The signed PDF is self-contained. Everything needed to verify it is embedded in the file. No server, no account, and no internet connection to SignNada is required.
What does "unable to verify" mean?
It means one or more signatures could not be confirmed, or the document hash does not match. This can happen if the document was modified after signing or if the file is not a SignNada-signed PDF.

LEGAL AND IDENTITY

Is this legally recognized?
Electronic signatures are recognized in most jurisdictions. SignNada meets the requirements of the ESIGN Act and UETA (United States) and qualifies as a Simple Electronic Signature under eIDAS (European Union). Each signer verifies their email, reviews the entire document, and signs with a cryptographic key generated in their browser. The signed PDF contains the full evidence chain. SignNada does not provide legal advice.
What identity verification does SignNada perform?
Each signer must verify access to their email address via a one-time code. This confirms inbox access, not legal identity. The sender is responsible for confirming that each email address belongs to the intended signer.
How It Works — Free Online Document Signing — SignNada