After the certificate has expired – is my digital signature still valid?

How long is a certificate valid?

Certificates for digital signatures are only issued for a certain period of time, usually one, two or five years.

This is purely for technical reasons. It is expected that after a few years the signature technology will have changed so much that new certificates will have to be issued anyway. Since each certificate change means additional work for the signer, GLOBALTRUST recommends the use of certificates that are valid for four years (or longer).

A signature remains valid even after the certificate has expired, at least as long as the procedure itself is classified as secure. This is particularly important for the tax audit, which stipulates a seven-year retention period for invoices.

Has your certificate expired? Order a new one now!

Do I have to resign the document after it has expired?

A new signature is by no means necessary, and in most cases not even possible or sensible (think of employees who have left the company). Unfortunately, many self-written programs (including Adobe Acrobat) do not implement these X509v3 specifications correctly. A check should show that the signature is valid for an unchanged document, the document is intact, and the signature was applied before the expiration date.

Even with revoked certificates, all signatures before the time of revocation remain valid. In principle, this is comparable to a credit card. If you shop with it and conclude a contract, then of course it remains valid, even if the card has long since expired.

The only decisive criterion is that the signature was made within the validity period and had not yet been revoked at the time the signature was provided.

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