The difference between a recognized and a qualified signature

When signing with a certificate, using what is known as a qualified certificate issued by an independent certification authority makes it possible — from a legal standpoint — to create two levels of signatures: recognized and qualified.

Qualified certificate stored outside a qualified device = recognized signature

• Legal standpoint: a recognized signature is required for dealings "with public administration" — that is, this is how a natural person or a representative of a legal entity must sign when communicating with public administration.
• A recognized electronic signature is created based on a qualified certificate stored on a "non-QSCD" device (an uncertified device), typically any PC or Mac.
• If the qualified certificate was not issued on a QSCD device, its properties contain the Policy Identifier OID 0.4.0.194112.1.0.

Viewing the certificate properties on a computer (in the Windows store — Certmgr):

Viewing in Adobe Reader (after displaying the Signatures panel):

Qualified certificate stored on a qualified device = qualified signature

• Legal standpoint: a qualified signature is required for the acts "of public administration" — that is, this is how a representative of public administration must sign.
• A qualified electronic signature is created only based on a qualified certificate stored on a QSCD device, typically in the form of a card or USB token.
• If the qualified certificate was issued on a QSCD device, its properties contain the Policy Identifier OID 0.4.0.194112.1.2.

Viewing the certificate properties on a computer (in the Windows store — Certmgr):

Viewing in Adobe Reader (after displaying the Signatures panel):

Lower signature levels

From a legal standpoint, there are also signatures at the advanced and basic levels. Documents signed with these can also have embedded certificates, but those will be shown as unverified. This does not mean they are invalid — only that the signatures are not recognized or qualified.