Method for setting up a communication channel between a server device and a client device

1. A method for initial setting up of a communication channel for exchanging data between a server device and a client device, comprising:

creating, by an issuer device, authentication information related to the client device prior to receiving a server inquiry, wherein the issuer device is separate from the client device;

receiving, by the client device, the server inquiry,

after receiving the server inquiry by the client device, requesting, by the client device, the authentication information from the issuer device;

after the requesting by the client device the authentication information from the issuer device, transmitting the authentication information from the issuer device to the client device, wherein the authentication information is a JavaScript Object Notation(JSON) Web Token and wherein the authentication information is not authorization information;

after the transmitting the authentication information from the issuer device to the client device, transmitting the authentication information from the client device to the server device in a cryptographic security protocol, wherein the cryptographic security protocol is a Transport Layer Security(TLS) handshake protocol having an extension for transmitting the JavaScript Object Notation (JSON) Web Token;

authenticating the client device by the server device using the cryptographic security protocol including the authentication information, wherein authenticating the client device depends on the transmitted authentication information and depends on an estimation of a reliability of the issuer device and not a reliability of the client device; and

setting up the communication channel between the server device and the authenticated client device using the cryptographic security protocol including the transmitted authentication information.

2. The method as claimed in claim 1 , wherein the authentication information is assigned an issuer device indicating an issuer of the authentication information.

3. The method as claimed in claim 1 , which furthermore comprises:

storing a permissibility list in the client device and/or in the server device, which permissibility list indicates which issuer device from a multiplicity of issuer devices can create authentication information that is permissible for authenticating the client device;

checking, in the client device or in the server device, whether the issuer device assigned to the authentication information is permissible in accordance with the permissibility list; and

if the issuer device is permissible in accordance with the permissibility list, authenticating the client device by means of the server device on the basis of the authentication information.

4. The method as claimed in claim 1 , wherein the authentication information is assigned destination information indicating destination server device information for which the authentication token is intended; and wherein the method furthermore comprises:

checking by means of the client device whether the destination server device information corresponds to the server device that communicated the enquiry to the client device; and

if the destination server device information corresponds to the server device, transmitting the authentication information from the client device to the server device.

5. The method as claimed in claim 1 , which furthermore comprises:

selecting, in the client device, from a multiplicity of items of authentication information an item of authentication information which is assigned an issuer device permissible in accordance with the permissibility list and/or which is assigned destination server device information corresponding to the server device, that asked for the authentication information; and

transmitting the selected authentication information from the client device to the server device by means of the cryptographic security protocol.

6. The method as claimed in claim 1 , which furthermore comprises:

if the client device is not authenticated by the server device, blocking the set-up of the communication channel between the server device and the client device.

7. The method as claimed in claim 1 , which furthermore comprises:

transmitting client device-related information from the client device to the issuer device; and

creating the authentication information taking account of the client device-related information in the issuer device.

8. The method as claimed in claim 1 , wherein the authentication information comprises at least one item of handling information indicating indications for proper transmission and/or use of the authentication information, and wherein transmitting the authentication information and/or authenticating the client device are/is carried out taking account of the handling information.

9. The method as claimed in claim 1 , furthermore comprising:

storing an issuer device list in the client device, which indicates the issuer devices from which the client device has valid authentication information and/or from which the client device can request authentication information.

10. The method as claimed in claim 1 , furthermore comprising:

requesting the authentication information for the client device by means of the server device by way of the cryptographic security protocol from the client device.

11. The method as claimed in claim 1 , wherein the authentication information furthermore contains a session information about a current connection between the client device and the server device.