Electronic Signature (E-signature)

Three levels of e-signatures

Under the EU's eIDAS regulation, e-signatures come in three legal tiers, each with increasing security and evidentiary weight:

• Simple Electronic Signature (SES) — typing your name, clicking "I agree", or drawing a signature with your finger. Legally valid for most business use cases.
• Advanced Electronic Signature (AES) — uniquely linked to the signer, capable of identifying the signer, and tamper-evident. Usually involves an email verification and audit trail.
• Qualified Electronic Signature (QES) — an AES created using a qualified certificate issued by a regulated Trust Service Provider. Legally equivalent to a handwritten signature in the entire EU.

The US ESIGN Act doesn't use this tiered model but follows a similar "intent to sign + attribution + integrity" principle for legal validity.

What makes an e-signature legally binding

1. Intent to sign — the signer must clearly intend to sign (not an accidental click)
2. Consent to electronic signing — both parties agree to do business electronically
3. Attribution — the signature can be linked to the specific signer
4. Integrity — the signed document hasn't been altered after signing
5. Retention — a copy is kept accessible to both parties

Which type do you actually need?

• Simple (SES) — contracts, invoices, quotes, NDAs, service agreements, proposals
• Advanced (AES) — employment contracts, lease agreements, loan applications, HR forms
• Qualified (QES) — real estate deeds, notarized documents, some government filings, cross-border EU contracts

For 95% of business documents, a simple e-signature with an audit trail (signer identity, IP, timestamp) is sufficient and legally enforceable. Konomic's Sign Request produces this level.

E-signature vs digital signature

These terms are often confused. An electronic signature is the broad legal concept (any digital signing method). A digital signature is a specific cryptographic technique using public-key cryptography (PKI) — one of the ways to implement an advanced or qualified e-signature. All digital signatures are electronic signatures, but not all electronic signatures are digital signatures.