In short
- Handwritten: signed with finger, pen or mouse in the form; the server binds it to the document with a SHA-512 signature.
- Per form: "Sign the PDF when it is submitted" in the release dialog; forms with sign-in are signed with the user's own key at the CodeB server, all others get the seal of the organisation.
- Long-term: signatures from the CodeB signing service reach PAdES B-LTA: signature timestamp, validation data (certificates and OCSP responses) and an archive document timestamp.
- X.509: text fields named
esignaturebecome PDF signature fields for certificates and smart cards (advanced and qualified signatures).
Handwritten electronic signatures
Signature fields can be signed with a finger or pen on phones and tablets, or with the mouse on a desktop. Your devices become a signature pad without buying hardware or installing an app.
- The signature is bound to exactly one document by a SHA-512 digital signature of the server.
- The server signature can carry a timestamp from an RFC 3161 time stamping authority, such as the Aloaha Timestamping Server.
- All communication between the device and the server is encrypted with TLS.
Typical uses: signatures in a branch or at the counter, field staff collecting signatures on site, and confirmations of visits or deliveries.
Digital X.509 signatures
Name a text field esignature in the designer and it becomes a PDF signature field. After submission the user opens the confirmed PDF in Adobe Reader, clicks the field and signs with a certificate or smart card. A submit button sends the signed PDF to the business owner of the form.
Signature levels under eIDAS
The EU regulation eIDAS distinguishes three levels of electronic signature.
| Level | What it is | With the eForms Server |
|---|---|---|
| Simple (SES) | Any electronic sign of intent, for example a drawn signature. | Handwritten signature, sealed and timestamped by the server. |
| Advanced (AES) | Uniquely linked to the signer, detects later changes. | Signature with the personal key of the signed-in person at a CodeB server (forms with sign-in), or an X.509 signature field with a personal certificate. |
| Qualified (QES) | Advanced signature with a qualified certificate on a secure device. | X.509 signature field with a qualified smart card, for example with the Aloaha PDF Signator. |
What the server records
When a form with a handwritten signature is submitted, the server renders the complete form including the signature image as PDF and seals it with its own digital signature (SHA-512). Any later change to the PDF breaks the seal, which PDF readers such as Adobe Reader show. With an RFC 3161 timestamp server configured, the seal also proves when the document was signed. The submitter and the form owner receive the same sealed PDF.
For a stronger level, forms can require sign-in with a verified identity, for example the EU Digital Identity Wallet, and the PDF records how the person signed in.
Seal or sign each submission
Whether the PDF of a submission is signed is set per form: tick Sign the PDF when it is submitted when you release the form. The server then signs every submitted PDF in this order:
- Forms that require sign-in with a CodeB server (for example phone.codeb.io) are signed with the personal key of the signed-in person at that same server. The server uses the person's sign-in for this, so nobody has to install software or enter a certificate password.
- All other forms receive the seal of the organisation: from the CodeB signing service with a dedicated account, or from a certificate on the form server itself.
- If the personal signature is not possible, for example because the person's key needs a PIN, the PDF receives the seal of the organisation instead, so no submission is lost.
Signatures from the CodeB signing service are advanced electronic signatures in PAdES format (not qualified) and are invisible on the page; PDF readers list them in the signature panel. By default they reach level PAdES B-LTA:
- B-T: an RFC 3161 timestamp proves when the PDF was signed.
- B-LT: the certificates and OCSP responses are embedded, so the signature can be checked later without the original servers.
- B-LTA: an archive document timestamp protects the signature and the validation data.
The signing service reports the level it delivered. A PDF below the lowest level you accept (a setting) is sealed by the organisation instead. Forms with a handwritten signature are always sealed.
Frequently asked questions
Is a handwritten signature in a web form legally valid?
It is a simple electronic signature under eIDAS. The eForms Server binds it to the document with a server signature and an optional timestamp, so later changes are detected.
Can forms be signed with a smart card?
Yes. Fields named esignature become PDF signature fields that can be signed in Adobe Reader with X.509 certificates and smart cards.
What is the difference between a sealed PDF and a signed PDF?
The seal is the server's digital signature over the submitted form: it proves the document has not changed since submission. A personal X.509 signature is made by the signer with their own certificate or smart card in the esignature field.
Do I need a signature pad?
No. Phones and tablets work with a finger or pen, desktops with the mouse; no hardware or app is needed.
Can the person who fills in the form sign it with their own key?
Yes, if the form requires sign-in with a CodeB server and is set to be signed on submission. The submitted PDF is then signed with the personal key of the signed-in person at the server that signed them in, as an advanced electronic signature (PAdES, not qualified). If that is not possible, the PDF gets the seal of the organisation.
Can I choose which forms are signed?
Yes. Tick or clear "Sign the PDF when it is submitted" when you release the form. Forms with a handwritten signature are always sealed.
Can a signed PDF still be verified in ten years?
A PAdES B-LTA signature carries its own validation data and an archive timestamp, so it can be checked without the servers that issued the certificates. To keep it verifiable beyond the lifetime of the timestamp certificate, a new archive timestamp has to be added before that certificate expires.
What happens if the timestamp service is down?
The signer's own signature is then made without a timestamp (level B-B), as long as the lowest accepted level allows it; otherwise the PDF receives the seal of the organisation. The level reached is written to the server's event log.
Can submitters sign the PDF with their own wallet?
Yes, with CodeB Wallet: release the form with "After submitting, offer to sign the PDF in CodeB Wallet" (forms that require sign-in with a CodeB server). After the normal submission the person gets a link, signs the PDF in the wallet, and the signed PDF goes to them and the form owner. Details on the EUDI Wallet page.
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