[zinekeller]

If the target is legal recognition then you need to store your legally-recognized name and need to do what patio11 calls a hybrid system - part-offline, part-online verification. Also, IIRC there's a free government CA in Estonia that can sign documents, but of course you need to trust that Estonia is both not malicious and not incompetent.

[sam_lowry_]

You can hack eIDs in several EU countries to sign documents.

Definitely possible in Belgium.

[M95D]

Link, please!

[sam_lowry_]

What link? eID certificates don't have the Signature attribute set to true, but one can still sign with these certificates, ignoring the attribute.

[M95D]

Link to a "how to" web page.