that attempts at decryption of uid to oid result in a great number of identities which makes it impossible to link a specific uid to the corresponding oid then uid is encrypted by means of a reversible algorithm alg 2 which is also produced at random by the hardware component 10 for generating a storage identity sid as follows alg 2 f kr r random number uid sid alg 2 is such that there exists a corresponding decrypting algorithm alg 3 by means of which sid can be decrypted in order to recreate uid the storage identity sid is used as described in step 4 above as encrypted record identifier when storing encrypted data element values dv in the operative database o db step 3 production of encrypted data element values dv the descriptive information di associated with the original identity oid is converted into one or more encrypted data element values dv linked to a data element type dt each the encryption takes place as described below with a reversible encryption function f kr which like the algorithms alg 1 and alg 2 above is also produced at random by the hardware component 10 the invention is distinguished by a compelling calling here being sent to the data element protection catalogue in the database iam db for automatic collection of the protection attribute which is linked to the data element type at issue.