Patent ID: 6981147

Claim:
A method of creating certificates with redundant information to certify keys of a user, wherein each of the certificates comprises a defined number of data elements which at least contain information on a certification body or issuer of the certificate, a user of the certificate and a key certified by the certificate, comprising the following steps: a) creation by the certification body of a basic certificate for use in connection with the several keys of the user, the basic certificate containing a single recitation of a defined number of data elements therein which elements are identical or redundant if repeated in separate certificates one for each of the several keys of the user in conjunction with the certification body; b) addition of an identifying characteristic to the basic certificate; c) generation of a digital signature for the basic certificate; d) addition of the digital signature to the basic certificate; e) generation of a key pair; f) creation of a supplementary certificate for the basic certificate which does not recite the redundant data elements contained in the basic certificate but does contain a key as set out in step e), the identifying characteristic as set out in step b) and additional data fields not registered by the basic certificate; g) generation of a digital signature for the supplementary certificate; h) addition of the digital signature to the supplementary certificate; and i) use of the basic certificate created in step a) for other of the several keys in additional supplementary certificates that share with the supplementary certifactes of step f) the redundant information recited in the basic certificate but like the supplementary certificate of step f) do not recite the redundant data elements.