Method for realizing an access management of a plurality of computing devices or functionalities or software applications executed thereon, by means of an access management entity especially serving a plurality of groups of persons, wherein the access management of the plurality of computing devices or functionalities or software applications executed thereon is related to health data of a plurality of persons, each of which is wearing or carrying a computing device or functionality of the plurality of computing devices or functionalities, to provide contact tracing based on detecting relevant encounters between two persons of the plurality of persons, wherein, regarding the plurality of computing devices or functionalities or software applications executed thereon, virtual device identifiers are used, wherein a virtual device identifier is related to a computing device or functionality or its software application, wherein the access management entity is provided with the private key of a key pair comprising the private key and a corresponding public key, wherein the method comprises the following steps in order for the computing device or functionality or its software application being at least one of authorized, authenticated, granted access, and group associated, by the access management entity: -- in a first step, the access management entity generates the virtual device identifier, encrypts it using the public key to obtain an encrypted virtual device identifier, and transmits the encrypted virtual device identifier to the computing device or functionality or its software application, -- in a second step, upon the computing device or functionality or its software application requesting, from the access management entity, the at least one of authentication, authorization, access, and group association, the computing device or functionality or its software application transmits the encrypted virtual device identifier to the access management entity and the access management entity grants this request based on the content of the virtual device identifier, obtained by means of decrypting, using the private key, the encrypted virtual device identifier received from the computing device or functionality or its software application. wherein, regarding the plurality of computing devices or functionalities or software applications executed thereon, virtual device identifiers are used, wherein a virtual device identifier is related to a computing device or functionality or its software application, wherein the access management entity is provided with the private key of a key pair comprising the private key and a corresponding public key, wherein the method comprises the following steps in order for the computing device or functionality or its software application being at least one of authorized, authenticated, granted access, and group associated, by the access management entity: -- in a first step, the access management entity generates the virtual device identifier, encrypts it using the public key to obtain an encrypted virtual device identifier, and transmits the encrypted virtual device identifier to the computing device or functionality or its software application, -- in a second step, upon the computing device or functionality or its software application requesting, from the access management entity, the at least one of authentication, authorization, access, and group association, the computing device or functionality or its software application transmits the encrypted virtual device identifier to the access management entity and the access management entity grants this request based on the content of the virtual device identifier, obtained by means of decrypting, using the private key, the encrypted virtual device identifier received from the computing device or functionality or its software application. -- in a first step, the access management entity generates the virtual device identifier, encrypts it using the public key to obtain an encrypted virtual device identifier, and transmits the encrypted virtual device identifier to the computing device or functionality or its software application, -- in a second step, upon the computing device or functionality or its software application requesting, from the access management entity, the at least one of authentication, authorization, access, and group association, the computing device or functionality or its software application transmits the encrypted virtual device identifier to the access management entity and the access management entity grants this request based on the content of the virtual device identifier, obtained by means of decrypting, using the private key, the encrypted virtual device identifier received from the computing device or functionality or its software application.