Understanding Adobe warnings on BankID-signed documents

Understanding BankID Signatures and Adobe Warnings

When working with electronically signed documents, especially those signed through BankID, users may sometimes notice a yellow warning in Adobe Acrobat or other PDF readers. This can cause confusion about the validity or security of the signature. Here’s a quick explanation to clarify what’s happening and why these warnings appear.

BankID and Certification Authorities

BankID is a widely used electronic identification and signature system, but it is not a certified certificate authority (CA). This means that when BankID generates a digital signature, it does so using a self-signed certificate rather than a certificate issued by a trusted CA.

What Is a Self-Signed Certificate?

A self-signed certificate is one that is signed by the same entity that created it, instead of a recognized CA. While technically secure, self-signed certificates are not inherently trusted by systems like Adobe Acrobat, which maintain their own lists of trusted certificate authorities.

Why the yellow warning in Adobe?

Adobe software flags self-signed certificates because it cannot automatically verify their trustworthiness. When you open a document signed via BankID, Adobe may display a yellow warning, suggesting that the signature is valid but not certified as “qualified”.

This does not mean the document has been tampered with or is insecure. It simply reflects that the certificate used does not come from a CA recognized by Adobe.

Qualified Electronic Seals

To enhance the trustworthiness of the document, BankID also applies a qualified electronic seal to the signature. A qualified seal confirms the identity of the organization that signed the document and ensures the content has not been altered. This seal is fully compliant with eIDAS regulations, which govern electronic identification and trust services within the EU.

In Summary

• BankID uses self-signed certificates, not CA-issued ones.

• Adobe flags these with a yellow warning, but the signature is still valid.

• A qualified electronic seal is added, which confirms the integrity and origin of the document.

• There is no need for concern if you see a yellow warning in Adobe, as the document remains legally and technically sound.