What Evidence Must an Electronic Signature Service Preserve

When a document is signed electronically, its validity and probative strength depend directly on the service’s ability to demonstrate in a verifiable and auditable way the entire signing process. That is, that the requirements of identification, integrity, and consent demanded by the eIDAS Regulation (European electronic identification regulation) are met.

Technical evidence is what converts a digital action into solid proof before a court. Therefore, an electronic signature service must record, seal, and preserve all information to reconstruct the signing event with maximum precision.

What is meant by “technical evidence”

Evidence is the set of automatically generated data during the signing process that, when integrated and sealed, allows demonstrating:

• Identification: Who participated in the process.
• Consent: That the signer acted voluntarily.
• Integrity: That the content has not been altered since the moment of signing.
• Chronology: When and from where the event was performed.

This evidence is the probative support that shields the legal validity of the electronically signed document.

Types of evidence that a signature provider must preserve

Although the eIDAS Regulation does not establish a closed list, technical standards (such as those defined by ETSI) and legal practice define these elements as essential:

1. Identification and Authentication Data Record of email address, phone number (for OTP), IP, geolocation, device, or any other data used to authenticate the signer and guarantee their exclusive control over the action.

2. Consent Proof Auditable record of the exact moment when the signer accesses the document, reviews it, and executes the signing action (click, OTP acceptance, biometric tracing, etc.).

3. Integrity Guarantee (Hash or Digital Fingerprint) Calculation of a unique cryptographic fingerprint (hash) of the document after signing. This hash mathematically demonstrates that the signed content did not suffer any modification.

4. Complete Chronological Record (Audit Trail) Detailed sequence of all process events: invitation sending, access, signing action, validation, and storage. It is the unalterable timeline of the process.

5. Provider’s Electronic Seal Signature or seal of the trust service itself on the generated evidence. This guarantees that the evidence is not altered and that the process traceability remains intact from the origin.

6. Secure Evidence Preservation Long-term custody of the set of evidence in an integral, encrypted form with the possibility of subsequent verification, ensuring its accessibility and usability for any requirement.

Generation and Presentation of the Evidence Document (Signature Proof)

The final result of this process is a verifiable document, known as Evidence Report or Signature Certificate, which is inseparably linked to the signed PDF.

In eEvidence, this document is generated automatically and includes:

• Detailed identification of the sender and signer.
• Complete copy of the signed document.
• Cryptographic fingerprints (hash) from its content.
• Technical record (audit trail) of each interaction and action.
• eEvidence’s digital signature to guarantee its inalterability and integrity as a trusted third party.

The set of these elements constitutes the complete proof of the electronic signature and can be presented directly before a judge or administrative authority with full legal guarantees.

Why evidence preservation is key

An electronic signature without verifiable and sealed evidence lacks solid probative strength.

A signature system that preserves complete and audited traceability allows demonstrating before any requirement:

• That the signer’s identity and consent were authentic and exclusive.
• That the document was not altered after signing.
• That the process was carried out in accordance with a trust service under eIDAS standards.

That’s why preserving evidence is not just a technical issue, but an essential legal obligation to shield the validity of any digitally signed document.

Frequently Asked Questions (FAQ)

How long should evidence be preserved?

It depends on the commercial, civil, or tax regulations applicable to the document. In general, a minimum of 5 to 10 years is recommended, or throughout the contract’s validity, plus the statute of limitations period for legal actions.

Who has the right to access evidence?

The service provider must guarantee access to the signing parties and, in case of litigation, to the competent judicial or administrative authority, so they can verify the process integrity.

Can evidence be altered over time?

No, if they are correctly sealed and digitally signed by the trust service provider. Timestamps guarantee their validity and that any subsequent manipulation would be immediately detectable.

Is a signature without evidence still valid?

Yes, it can be valid, but it will have very limited probative strength. Without technical traceability, it is difficult to prove its authenticity and it is easily challengeable before a court.

Conclusion

The legal value of an electronic signature depends both on the act of signing and on the evidence that demonstrates how it was signed. Recording, sealing, and preserving this data is what converts a digital process into legally solid proof.

Solutions like eEvidSign from eEvidence not only allow managing signature flows with the required security (simple or advanced), but also preserve and custody all technical evidence associated with each signature. This ensures traceability, integrity, and maximum legal validity of documents over time.