Signatory Identity and Digital Proof
How to prove who signed an electronic document? Identification techniques, assurance levels and KYC issues explained.
Certyneo Team
Editor — Certyneo · About Certyneo
The Heart of the Problem
An electronic signature has value only if you can prove who affixed it. A simple click on "I Accept" says nothing reliable about identity.
Identification Techniques
Trusted Email
Unique link sent. Only the mailbox holder can click. Basis of simple signature (SES).
OTP via SMS
One-time code sent to the number. Combined with email, it's the standard for advanced signature (AES).
Video KYC
Verification by videoconference: identity document, liveness test, OCR. Used for QES and regulated sectors.
Qualified Certificate
Personal cryptographic certificate issued by a QTSP. Highest level, required for QES.
National Digital Identity
FranceConnect+, itsme (Belgium), SPID (Italy). EUDIW wallets will extend this option.
Assurance Levels (LoA)
eIDAS defines three levels:
- Low: simple email → SES
- Substantial: dual factor → AES
- High: strict verification → QES
GDPR Issues
Identification collects personal data. GDPR requires:
- Minimisation (collect only what is necessary)
- Documented retention period
- Right of access and erasure
- Legal basis (contract performance, article 6.1.b)
Biometric data (video KYC) is sensitive — explicit consent required.
KYC and Regulated Sectors
Banks, insurers, crypto, real estate brokers are subject to AML-CFT. KYC requires:
- Identity document verification with OCR
- Liveness test (dynamic selfie)
- Cross-checking against sanctions lists (PEP, OFAC)
- Sometimes human operator via video
Mistakes to Avoid
- Relying on email alone for sensitive contracts
- Storing identity documents indefinitely
- Failing to document the legal basis
- Collecting more than necessary
Use Case: Opening a Neo-Bank Account
- Information entry (name, address, profession)
- Upload identity document + proof of address
- Liveness test: dynamic selfie
- Contract signature in AES with SMS OTP
In 10 minutes, account opened with "substantial" identification acceptable to the ACPR.
How Certyneo Helps You
Certyneo natively offers email + SMS OTP identification (AES). For cases requiring enhanced KYC, a video KYC integration is available: document verification, liveness test, sanctions cross-checking.
KYC data is hosted in the EU, encrypted, with documented retention periods in compliance with GDPR.
Discover the Certyneo electronic signature solution
FAQ
Is email alone sufficient for a valid signature?
Technically yes for SES. For a document at stake, opt for AES with SMS OTP.
Does GDPR prohibit storage of identity documents?
No, it regulates it. Legal basis, limited duration, enhanced security for sensitive data.
Can FranceConnect+ be used?
Yes, recognised "substantial" level for AES or even QES.
Is video KYC mandatory for insurance?
Not as such, but the ACPR expects enhanced identification.
Can I sign with an identity from another EU country?
Yes, mutual recognition of eIDAS (itsme, SPID, nPA).
Conclusion
Identification is the weakest link in the chain of proof. Care for it according to the stakes, and your signature will be solid.
Try Certyneo to send, sign and track your documents online simply, quickly and securely.
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Go deeper
Reference articles on this topic.
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