What is an electronic signature? The definition that counts

Regulation (EU) No 910/2014 defines it in article 3(10): data in electronic form, attached to or logically associated with other data in electronic form, used by the signatory to sign. The regulation deliberately says nothing about the technology — a scanned image of a signature pasted into a PDF, a drawn line in a browser, or a cryptographic signature are all, in the bare legal sense, electronic signatures.

What the regulation adds on top of the definition is the article 25(1) floor: an electronic signature may not be denied legal effect or admissibility as evidence in legal proceedings solely because it is electronic.

Federal law reaches the same floor without any tier. The ESIGN Act, 15 U.S.C. §7001(a), provides that a signature or record in interstate or foreign commerce may not be denied legal effect, validity or enforceability solely because it is electronic. State law fills in the detail through UETA — the Uniform Electronic Transactions Act — which most states have enacted and which likewise bars denying effect solely for being electronic (UETA §7).

No cryptography, no certificate, no platform: the legal definition is about the act of signing in electronic form, not about the strength of the proof behind it. That is why two questions follow the definition: whether the signature may be denied effect solely for being electronic (the statutory floor says no), and whether the evidence behind it would convince anyone it means what it says.

The evidence quality — who signed, that the bytes did not change, when — is not part of the definition. It is what a signing service is actually for: turning a legally sufficient act into one you can prove later.

Regulation (EU) 2024/1183, which entered into force on 20 May 2024, amends eIDAS to establish the European Digital Identity Framework: Member States must provide citizens with a European Digital Identity Wallet by the end of 2026. For signatures, the article 25 floor and the qualified/advanced structure carry over; the wallet adds a state-backed way to assert identity — which, over time, strengthens the identity step of signing flows.