Quick answer: In Turkey a qualified (secure) electronic signature carries the same legal effect as a handwritten wet signature under Electronic Signature Law No. 5070. Mobile signature is a type of electronic signature based on a qualified certificate the operator places on the SIM card. Registered electronic mail (KEP) is an official communication channel that records the time and content of a message with legal evidentiary value. In a dispute, the validity of these signatures is examined forensically through the certificate chain, the timestamp and document integrity.

Types of electronic signature and legal value

An electronic signature is not one single thing. Its legal effect varies with the technical assurance behind it. In practice three levels are described.

Signature type Technical basis Legal equivalence
Simple electronic signature Scanned signature, name at the end of an email Weak, does not replace a wet signature on its own
Advanced electronic signature Bound to the signer, tamper evident method Has evidentiary value, depends on conditions
Qualified (secure) electronic signature Qualified certificate, secure signing device Same legal effect as a wet signature

The genuinely strong one in Turkey is the qualified electronic signature. Under Law No. 5070, a secure electronic signature has the same evidentiary force as a handwritten signature, except for certain transactions that laws subject to a formal form or a special ceremony. Only Electronic Certificate Service Providers authorized by the ICTA (BTK) may issue a qualified certificate.

What is mobile signature and how does it differ from e-signature?

Mobile signature is also a qualified electronic signature. The difference is that the certificate is stored on the SIM card of the mobile phone rather than on a separate USB token. The user approves the signing request on a screen that appears on the phone with a personal PIN.

  • A classic e-signature usually requires a hardware token and a card reader.
  • Mobile signature only needs a phone and an operator subscription.
  • Both belong to the qualified signature category with the same legal effect.

So in practice the difference is not legal but about convenience. Mobile signature is more practical in field use and remote approval processes.

KEP: why is registered electronic mail different?

KEP differs from ordinary email. With normal email it is hard to independently prove when a message was sent and with what content. In the KEP system, the time of a message, its content and its delivery to the other party are documented with evidence records the system produces.

The Turkish Commercial Code provides that certain notices and objections between merchants may be made via KEP. This makes KEP a strong evidence tool in official service and commercial correspondence. The core difference between ordinary email and KEP is as follows.

Feature Ordinary email KEP
Proof of send time Weak, disputable Recorded by the system
Content integrity Not guaranteed Under record
Legal service value Limited Defined by legislation

Forensic examination of e-signature and KEP

In a dispute the question arises whether a document was really signed or altered afterward. Forensic examination of a digital signature looks at:

  • Certificate chain validation: Was the signature made with a valid certificate from an authorized provider.
  • Revocation status: Was the certificate valid according to revocation lists (CRL/OCSP) at the moment of signing.
  • Timestamp: Is the moment of signing confirmed by an independent timestamp.
  • Document integrity: Has the document's hash changed after signing, that is, was the content tampered with.
  • Signing context: Does the signature belong to the correct document, is the format valid.

These examinations must be performed so as to preserve the chain of custody. Otherwise the evidentiary value becomes disputable. Our separate articles detail the chain of custody and court admissibility.

The KAOS and DSET approach

DSET performs forensic examination of electronically signed and KEP recorded documents without breaking the chain of custody. We prepare a technical determination report on signature integrity, timestamp and certificate validity. This article is general information. For a specific dispute you should consult your lawyer for legal advice. Our field is technical determination and forensic examination at expert witness level.

Related reading: forensic evidence and court admissibility, are WhatsApp messages admissible as evidence, what is hash verification, forensic process and KVKK chain of custody, Ankara forensic expert witness opinion.

Frequently asked questions

Does a qualified electronic signature replace a wet signature? Yes. Under Electronic Signature Law No. 5070, a secure (qualified) electronic signature produces the same legal effect as a handwritten signature, except for transactions that laws tie to a formal form or a special ceremony. The qualified certificate must come from a provider authorized by the ICTA (BTK).

Is there a legal difference between mobile signature and e-signature? In terms of legal effect both are qualified electronic signatures with the same evidentiary force. The difference is technical. An e-signature usually needs a USB token and card reader, while mobile signature stores the certificate on the phone's SIM card and approves the signature from the phone with a PIN.

Is a message sent via KEP admissible as evidence in court? Because KEP documents the time and content of a message with records the system produces, it carries far stronger evidentiary value than ordinary email. Legislation provides that certain notices and objections between merchants may be made via KEP. For how evidentiary value is assessed in a specific case, legal advice is recommended.

Sources

For forensic examination of electronically signed or KEP recorded documents, you can talk to our team at Ankara Hacettepe Technopark. Contact DSET.