Timestamping guide

Timestamping electronic

Updated on June 28, 2026

Electronic timestamping (or electronic time stamp) proves that a document existed at a given moment and has not been modified since. Here is the difference between simple and qualified timestamping, its legal value under eIDAS and its concrete use cases.

What is electronic timestamping?

Electronic timestamping associates a precise date and time with data (a document, a signature) in order to establish proof that this data existed at that specific moment. Technically, a timestamping service signs the fingerprint (hash) of the document with a time mark, according to the standardized RFC 3161 protocol.

The European regulation eIDAS (EU) No. 910/2014 defines electronic timestamping in Article 3 and devotes Articles 41 and 42 to it. Timestamping is a "trust service": it guarantees both the date and the integrity of the timestamped data.

Concretely, once a document is timestamped, any subsequent modification breaks the fingerprint and invalidates the timestamp — this is what makes it robust proof of integrity, enforceable over time.

Simple vs qualified timestamping

eIDAS distinguishes two levels, with different legal effects.

Electronic timestamping (simple)

According to Article 41 of eIDAS, the legal effect and admissibility of an electronic timestamp cannot be refused solely on the grounds that it is in electronic form. It already constitutes useful evidence, without benefiting from legal presumption.

Qualified electronic timestamp

Issued by a qualified trust service provider (QTSP), it benefits from a presumption of accuracy of the date and time, as well as data integrity (art. 42 eIDAS). It is the time mark with the strongest evidentiary value.

What is electronic timestamping for?

Timestamping addresses three major legal and operational needs:

Proof of prior existence: proving that a document, creation or agreement existed before a given date (intellectual property, filing, contract).

Integrity over time: demonstrating that a file has not been modified since it was timestamped.

Strengthening electronic signature: the timestamp seals the moment of signature and enables long-term preservation (PAdES-LTV formats).

Archiving with evidentiary value: associated with electronic archiving, it guarantees the dating of preserved documents.

Regulatory compliance: logs, registers and evidence subject to reliable dating obligations.

Timestamping at Certyneo

Every document signed via Certyneo is timestamped and its fingerprint is sealed in the eIDAS evidence file, alongside the audit trail (identity, IP, OTP). The signature date is thus enforceable and the document integrity verifiable.

For the most demanding needs, qualified timestamping from a qualified trust service provider (QTSP) makes it possible to achieve the presumption of accuracy provided for in article 42 of eIDAS and long-term preservation of signatures.

Sources and resources

Frequently asked questions

What is the difference between simple and qualified timestamping?

Simple timestamping cannot be denied any legal effect on the grounds that it is electronic (art. 41 eIDAS), but it benefits from no presumption. Qualified timestamping, issued by a qualified provider (QTSP), benefits from a presumption of accuracy of the date and data integrity (art. 42 eIDAS).

Does electronic timestamping have legal value?

Yes. eIDAS recognizes electronic timestamping as a trust service. Qualified timestamping has the strongest probative value thanks to its legal presumption; simple timestamping remains admissible evidence.

What is RFC 3161?

RFC 3161 is the international technical standard that describes the Time-Stamp Protocol. A timestamping service signs the document''s fingerprint with a timestamp issued from a reliable time source.

Does timestamping prove that my document has not been modified?

Yes. Timestamping seals the document''s fingerprint (hash) at a given instant. Any subsequent modification changes the fingerprint and invalidates the timestamp — this is proof of integrity over time.

Is qualified timestamping required to sign a contract?

No, not systematically. Advanced electronic signature incorporating a timestamp is sufficient for the vast majority of contracts. Qualified timestamping is recommended for the highest evidential stakes and long-term preservation.