Re-signing of signatures

The focus is again on the immutability of the data which are supposed to be archived in the long term. It must be considered that a signature which is still secure today might be regarded as invalid later on (e.g. due to a key length which is not sufficient anymore). In case  of a legal dispute, it therefore must be proven that the signature was valid at the time when the signature was created.
According to § 17 of the German Signatures Act the re-signing procedure is applied, i.e. re-signing before he defined expiration of the qualification of an encryption algorithm. For the re-signing process new, valid algorithms and qualified time stamps are used accordingly.

If, however, the encryption algorithm or the certificates which were used, have become invalid, the digital signature will become invalid, too. A signature card which has become invalid would have the consequence that the signed documents cannot be used anymore.

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