The one who signs the document and the one who verifies it are in the same system
The module sets up four signing paths together: qualified electronic signature with a smart card or a USB token, mobile signature over a GSM line, a wet signature drawn on screen and a wet signature image uploaded from a file. Every signed document is written to the ledger and can be queried back with a verification code.
- The signing key never reaches the browserThe qualified signature is taken through the local signing service running on the user's own computer. The card PIN and the private key never leave the device; only the signed output goes to the server side.
- The signature record is bound to the documentEvery signing event is written to the ledger with the signer, the document title, the document type, the signature type, the signing time, the SHA-256 digest of the file and a sixteen-character verification code.
Supported signature types
The four below are set up as separate tabs in the module. A signature type that is not on this list does not exist in this module.
Qualified electronic signature
Signing with a smart card or a USB token. The local signing service finds the device, reads the certificate, verifies the PIN and produces the signed output; the digest algorithm is SHA-256.
Mobile signature
Signing through the mobile signature infrastructure tied to a GSM line. The subscription of the number is queried, a signing request lands on the phone, and the transaction is polled while approval is awaited.
Drawn wet signature
A signature drawn on a canvas with a mouse, a pen or a touch screen. The pen colour can be chosen and the drawing cleared and redone; the result is stored as a PNG in the form of the user's default signature.
Uploaded wet signature
Uploading an existing signature image from a file. PNG and JPEG are accepted, at most 5 MB; the image is resized on the server to a 600×200 bound and converted to PNG.
Signature formats
The format is chosen according to the type of the file being signed; the module picks the right one by looking at the file extension.
| Format | For which document | How it is chosen |
|---|---|---|
| PAdES-BES | PDF documents | Selected automatically when the extension is .pdf; exported reports are signed with this format. |
| XAdES-BES | XML documents | Selected automatically when the extension is .xml. |
| CAdES-BES | Other file types | The default format for every file other than PDF and XML. |
In all three formats the digest algorithm is SHA-256. The signed output is downloaded as a separate document alongside the file that was signed; the source file is not modified.
Qualified e-signature flow
Each of the six steps appears on screen as its own state; the user reads which step is being waited on and where it got stuck.
- Service checkFirst the network connection and then the local signing service running on the computer are probed. If the service is closed the screen shows both the start link and the retry button.
- Device scanConnected smart card readers and USB tokens are listed. If there is no device an insert the card warning appears; if there is more than one device you can switch between them.
- Reading the certificateThe certificate of the selected device is read; the certificate holder, the identity number, the issuing authority, the validity range and the device model appear on screen.
- PIN verificationThe PIN consists of digits only, is at most eight characters long and cannot be pasted into the field. A warning appears while Caps Lock is on; the entered value can be made visible on request.
- SigningThe progress bar shows three stages: verifying the PIN, signing, completed. The signing request is held for at most thirty seconds and returns as an error if no result arrives.
- Result and recordThe signed output is produced and the signing event is written to the ledger. After the first signature, storing the PIN bound to that device is offered; the offer can be declined.
Mobile signature flow
The mobile signature works asynchronously: the request is sent, the approval is given on the phone, and the system waits by polling for the result.
- Subscription queryWhether the entered number is a mobile signature subscriber is queried. If it is not, the flow stops before it starts and the reason is written on screen.
- Signing requestThe request is sent together with the description text that will appear on the phone; the user reads on their own screen which document they are approving.
- Transaction idWhen the request is accepted asynchronously a transaction id is returned and the screen moves into the awaiting approval on your phone state.
- Status pollingThe result is asked for every three seconds and waited for at most ninety seconds. If the time runs out the transaction closes with a timeout and has to be started again.
- ResultThree results are handled separately: signed, cancelled by the user, timed out. When a PDF is signed, the signature is embedded into the document and a signed copy is produced.
Situations met in the field
The module is built on the assumption that signing rarely finishes on the first attempt; eight situations are handled one by one.
Storing the PIN
With the user's consent the PIN is stored bound to the serial number of the device. The field is no longer empty on the next signature; the stored PIN can be deleted in one step.
Wrong PIN
When a wrong PIN is entered the warning is shown together with the number of attempts left; on the last attempt the warning is emphasised further.
Locked card
When the PIN is locked the screen moves to a warning state, the retry button is disabled and how to unlock the card is explained.
Caps Lock warning
While Caps Lock is on, a warning icon and a short explanation appear next to the PIN field; a mistyped PIN is prevented before it burns an attempt.
Card removed
Connected devices are probed every five seconds. If the card is removed during the operation the screen returns to the device scan and states that the connection was lost.
Second tab lock
If a second tab in the same browser starts signing, the other tab is locked; a single device is prevented from meeting two requests at once.
Certificate expiring
A warning is raised when fewer than thirty days remain to the end of the certificate and a critical warning when fewer than seven days remain or it has expired; signing does not open with an expired certificate.
Transient device error
On transient errors such as a dropped card session the operation is retried twice without showing an error to the user. If the error persists it is written together with its error code.
Signature ledger and verification
Who signed what and when can still be queried after the signed document has been downloaded.
- Ledger recordEvery signing event is written with the signing user, the organisation, the document type, the document title, the signature type, the signing time, the IP address and the browser information.
- File digestThe SHA-256 digest of the document is recorded; when queried with the same digest, the signature record the document belongs to is found.
- Verification codeA sixteen-character verification code in four blocks is generated for every record; letters and digits that are easily confused are not used in the code.
- Verification by QR codeA QR code carrying the verification address is printed on the exported document; when the code is scanned the validity of the record is queried.
- Ledger listSignature records are filtered by document type, signature type and user; they are searched over the document title and the verification code.
Signing in with an e-signature
The same infrastructure is set up for authentication as well as for document signing.
Sign-in with a certificate
The identity number or the e-mail address extracted from the signing certificate is matched against the user record; if there is no match no session is opened.
Sign-in with a mobile signature
The sign-in request lands on the phone and the session opens when it is approved; if the request is not signed or is cancelled the sign-in is refused.
Session cookie
At the end of verification the session token is issued in a cookie only the server can read and is valid for a limited time.
Frequently asked
The five questions asked most often about signature types, setup and verification.
Which signature types are supported?
Does anything have to be installed on the computer for a qualified signature?
Does a wet signature image replace a qualified signature?
How is the authenticity of a signed document queried?
What happens if the user does not approve a mobile signature?
Legal basis
The table shows the obligations of the legislation region you pick in the top bar; it refreshes without reloading the page when the region changes.
Legal basis — Türkiye
| Obligation | Legal basis | How the module covers it |
|---|---|---|
| An electronically signed document has the same legal effect as a handwritten signature | Law no. 5070 on Electronic Signature, art. 5 — a secure electronic signature has the same legal effect as a handwritten signature. Legal transactions that the laws subject to an official form or a special ceremony, and guarantee contracts other than bank letters of guarantee and surety bonds issued by insurance companies established in Türkiye, cannot be carried out with a secure electronic signature. | The module sets up qualified electronic signature and mobile signature on separate tabs; a drawn or uploaded wet signature image is a visual record printed on the document and does not replace a cryptographic signature. |
| The signature is uniquely linked to the signatory and later changes can be detected | Same Law, art. 4 — a secure electronic signature is uniquely linked to the signatory, is created with a secure signature creation device under the sole control of the signatory, and makes it possible to identify the signatory on the basis of a qualified electronic certificate and to detect any subsequent change to the signed electronic data. | The certificate holder, the identity number, the issuing authority and the validity range are shown on screen before signing; the SHA-256 digest of the signed file is written into the log. |
| The signature creation data never leaves the device | Same Law, art. 6(b) and 6(c) — secure electronic signature creation devices ensure that the signature creation data held on them cannot be extracted in any way and remains confidential, that it cannot be obtained or used by third parties, and that the electronic signature is protected against forgery. | A qualified signature is taken through the local signing service running on the user's own computer; the card PIN and the private key never leave the device. |
| A signed record can be kept electronically and verified afterwards | Regulation on Health and Safety Requirements in the Use of Work Equipment, art. 7(2)(c) — records signed with a secure electronic signature under Law no. 5070 on Electronic Signature and kept electronically are valid; this is the direct application of the electronic signature in occupational health and safety records. | Every signing event is written into the log with the signatory, the document title, the signature type, the signing time, the SHA-256 digest of the file and a sixteen-character verification code; the QR code printed on the document leads to the verification address. |
These rows are for Turkish legislation and the basis of every row was read from the downloaded source text. Administrative fine amounts change every year with the revaluation rate, so they are not kept in this table; the current amounts are published in the free penalty tables on this site.
Legal basis — European Union
| Obligation | Legal basis | How the module covers it |
|---|---|---|
| A qualified electronic signature has the equivalent legal effect of a handwritten signature | Regulation (EU) 910/2014 (eIDAS), Article 25(2) | The qualified electronic signature is taken with a smart card or USB token through the local signing service running on the user's own computer; the card PIN and the private key never leave the device and only the signed output reaches the server. |
| An electronic signature shall not be denied legal effect and admissibility as evidence solely because it is in electronic form or does not meet the requirements for qualified electronic signatures | Regulation (EU) 910/2014 (eIDAS), Article 25(1) | A drawn or uploaded handwritten signature image is printed on the document as a visual signature; a cryptographic signature is produced only through the qualified electronic signature and mobile signature paths, and because the ledger keeps the signature type separately the two are never confused. |
| An advanced electronic signature must be uniquely linked to the signatory, capable of identifying him, created using signature creation data under his sole control, and linked to the signed data so that any subsequent change is detectable | Regulation (EU) 910/2014 (eIDAS), Article 26 | Every signing event is written to the ledger with the signing user, the organisation, the document type and title, the signature type, the signing time, the IP address and the browser; the SHA-256 digest of the file is recorded, and querying that digest finds which signature record the document belongs to. |
| Validation of a qualified electronic signature requires that the certificate was qualified and valid at the time of signing, that the integrity of the signed data has not been compromised and that the advanced signature requirements were met | Regulation (EU) 910/2014 (eIDAS), Article 32(1) | The certificate holder, the identity number, the issuing authority and the validity period are shown on screen before signing, and signing does not open with an expired certificate. The exported document carries a QR code with the verification address, and the sixteen-character verification code queries the validity of the record. |
In the EU the framework for electronic signatures is Regulation 910/2014 (eIDAS); a regulation applies directly and needs no transposition. The certificate and the signature creation device required for a qualified signature come from a qualified trust service provider on the Member State's trusted list. Article numbers are read from the downloaded text of the regulation.
Legal basis — United Kingdom
| Obligation | Legal basis | How the module covers it |
|---|---|---|
| An electronic signature, and the certification of that signature by any person, are each admissible in evidence in relation to any question as to the authenticity or the integrity of the communication or data. | Electronic Communications Act 2000 (c. 7), s. 7(1) | Every signing event is written to the ledger with the signer, document title, document type, signature type, signing time, the file's SHA-256 digest and a sixteen-character verification code. |
| An electronic signature is so much of anything in electronic form as is incorporated into or otherwise logically associated with a communication or data and purports to be used by the individual creating it to sign. | Electronic Communications Act 2000 (c. 7), s. 7(2) — s. 7(2)(b) substituted by S.I. 2016/696 | Four signature types are set up as separate tabs: qualified electronic signature, mobile signature, drawn wet signature and uploaded wet signature. Because the ledger keeps the signature type separately, a cryptographic signature is never confused with a visual one. |
| An electronic seal and its certification are likewise admissible in evidence; an electronic seal is anything in electronic form incorporated into or logically associated with a communication or data that purports to ensure its origin and integrity. | Electronic Communications Act 2000 (c. 7), s. 7A(1)-(2) | The document's SHA-256 digest is recorded; querying the same digest finds which signature record the document belongs to. A QR code carrying the verification address is printed on the exported document. |
| A qualified electronic signature has the equivalent legal effect of a handwritten signature; an electronic signature may not be denied legal effect or admissibility as evidence solely because it is in electronic form or does not meet the requirements for a qualified signature. | Regulation (EU) No 910/2014 (retained as UK eIDAS), Article 25(1)-(2) | A qualified signature is taken through the local signing service with a smart card or USB token; the format is chosen by file type as PAdES-BES, XAdES-BES or CAdES-BES, and the digest algorithm is SHA-256 in all three. |
| An advanced electronic signature must be uniquely linked to the signatory, capable of identifying the signatory, created using signature creation data the signatory can use under their sole control with a high level of confidence, and linked to the signed data so that any subsequent change is detectable. | Regulation (EU) No 910/2014 (retained as UK eIDAS), Article 26 | The card PIN and the private key never leave the device; only the signed output reaches the server. The signed output is downloaded as a separate document and the source file is left unchanged. |
After 31 December 2020 the United Kingdom retained eIDAS in its own law as “UK eIDAS”; paragraph 3 of Article 25, which governed recognition across the EU, was revoked at that point. The evidential status of an electronic signature comes from section 7 of the Electronic Communications Act 2000, and the equivalence of a qualified signature to a handwritten one from Article 25(2) of Regulation 910/2014.
Legal basis — United States
| Obligation | Legal basis | How the module covers it |
|---|---|---|
| Do not deny validity to a signature, contract or record solely because it is electronic | 15 U.S.C. 7001(a)(1) — a signature, contract or other record relating to a transaction in or affecting interstate or foreign commerce may not be denied legal effect, validity or enforceability solely because it is in electronic form; (a)(2) — a contract may not be denied legal effect solely because an electronic signature or electronic record was used in its formation | The module carries four signature types as separate tabs: qualified electronic signature, mobile signature, a wet signature drawn on screen and a wet signature uploaded from a file. No signature type outside that list exists in the module. |
| The signature must be executed with the intent to sign the record | 15 U.S.C. 7006(5) — the term electronic signature means an electronic sound, symbol or process, attached to or logically associated with a contract or other record and executed or adopted by a person with the intent to sign the record | The signature is bound to a person: when the certificate is read, the holder, the identity number, the issuing authority, the validity range and the device model appear on screen, and the signer's diploma or registry number is verified in the signature panel. |
| Retain a required record as an electronic record that accurately reflects it and remains accessible | 15 U.S.C. 7001(d)(1)(A) — the electronic record accurately reflects the information set forth in the contract or other record; (d)(1)(B) — it remains accessible to all persons entitled to access, for the period required by law, in a form capable of being accurately reproduced for later reference | The signed output is downloaded as a separate document alongside the signed file and the source file is left unchanged; the SHA-256 digest of the document is stored, and querying by that digest finds which signature record the document belongs to. |
| The electronic record must be capable of being retained and accurately reproduced by the parties | 15 U.S.C. 7001(e) — where a record is required to be in writing, the legal effect, validity or enforceability of an electronic record may be denied if it is not in a form capable of being retained and accurately reproduced for later reference by all parties or persons entitled to retain it | Every signing event is written to the ledger: signing user, organisation, document type, document title, signature type, signing time, IP address and browser. A QR code carrying the verification address is printed on the exported document and a sixteen-character verification code in four blocks is generated. |
| Do not require, or give greater legal effect to, a specific technology | 15 U.S.C. 7002(a)(2)(A)(ii) — alternative State procedures may not require, or accord greater legal status or effect to, the implementation or application of a specific technology or technical specification for creating, storing, generating, receiving, communicating or authenticating electronic records or electronic signatures | A drawn or uploaded wet signature image is a record stamped onto the document as a visual signature; a cryptographic signature is produced only through the qualified electronic signature and mobile signature paths, and because the ledger keeps the signature type separately the two never blur. |
The ESIGN Act does not require any particular technology for a signature, and a state rule may not mandate a specific technology or accord it greater legal effect (15 U.S.C. 7002(a)(2)(A)(ii)). State law may modify the provisions of this subchapter to the extent it enacts the Uniform Electronic Transactions Act (15 U.S.C. 7002(a)(1)).
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