Why a warning appears in Adobe for signatures made via BankID

Why a warning appears in Adobe for signatures made via BankID (and why it isn't a problem)

When working with electronically signed documents, especially those signed via BankID, a yellow warning may appear in Adobe Acrobat or other PDF readers. This can raise questions about the validity or security of the signature. Let's explain why this happens and what it actually means.

BankID and certification authorities

BankID is a widely used system for electronic identification and signing, but it is not a certification authority (CA). This means that when generating an electronic signature, it uses a self-signed certificate, not a certificate issued by a trusted authority.

What is a self-signed certificate?

A self-signed certificate is a certificate that an organization signs itself. Although it is technically secure, systems like Adobe Acrobat do not automatically consider it trustworthy, because it is not issued by an officially recognized certification authority.

Why does Adobe show a yellow warning?

Adobe marks signatures with self-signed certificates with a yellow warning because it cannot automatically verify their trustworthiness. When you open a document signed using BankID, Adobe may display a warning that the signature is valid but not qualified.

However, this does not mean that the document is invalid or unsafe. It is merely a technical notice.

Qualified electronic seal

To make the document more trustworthy, BankID also adds a qualified electronic seal to the signature. This confirms the identity of the organization that signed the document and ensures its integrity. The seal is fully compliant with the eIDAS regulation, which governs electronic identification and trust services in the EU.

Summary

• BankID uses self-signed certificates, not certificates from recognized CAs.

• Adobe marks them with a warning, but the signature is technically fine.

• The document contains a qualified seal, which confirms its authenticity and integrity.

• The yellow warning in Adobe does not indicate a problem – the document is valid and secure.

This technical behavior may seem confusing, but it does not pose any risk. The trustworthiness of the document remains intact.