Secure key management device, authentication system, wide area network and method for generating session keys

1 . A secure key management device for a long range wide area network (LoRaWAN) comprising an end-device, a network server, an application server, and a join server, the secure key management device comprising:

a secure storage component for storage of secret key information;

a secure interface for securely exchanging data with the join server; and

at least one processing component configured to:

generate and store at least one master key in the secure storage component, wherein the secure storage component is distinct and separate from the at least one processing component;

generate, based on the at least one master key and a unique identifier of the end-device, at least one root key, and provide the at least one generated root key to the end-device;

receive, from the join server via the secure interface, a first request comprising the unique identifier of the end-device and session information;

generate, based on the at least one master key stored in the secure storage component, and the unique identifier of the end-device and the session information comprised in the first request, at least one session key; and

provide the at least one session key via the secure interface to the join server;

wherein a pre-registration procedure performed before the secure key management device receives the first request comprises generating and providing the at least one root key to the end-device and providing, by the secure key management device, the join server with a registration message comprising the unique identifier of the end-device.

2 . The secure key management device of claim 1 , wherein the secure key management device and join server are part of an authentication system for authenticating the end-device in the long range wide area network, wherein the authentication system further comprises:

at least one processing component of the join server which is configured to:

receive, from the end-device, a second request comprising address information of the end-device;

provide, via the secure interface to the secure key management device, the first request based on the address information of the second request; and

forward the at least one session key received via the secure interface from the secure key management device to at least one of the network server and the application server.

3 . The secure key management device of claim 2 , wherein the authentication system further comprises:

a registration device, connectable to the end-device and the secure key management device during the pre-registration procedure,

wherein at least one processing component of the registration device is configured to perform the following steps during the pre-registration procedure:

determine the unique identifier of the end-device;

provide a third request comprising the unique identifier of the end-device to the secure key management device;

receive the at least one root key provided by the secure key management device; and

securely store the at least one root key in the end-device.

4 . The secure key management device of claim 3 , wherein the at least one processing component of the registration device is further configured to perform the following steps during the pre-registration procedure:

determine an end-device address identifier for addressing the end-device in the wide area network; and store the end-device address identifier in the end-device.

5 . The secure key management device of claim 2 , wherein

the end-device is configured to send a data packet to the network server, the data packet being encrypted on a network layer and on an application layer;

the network server is configured to partially decrypt the data packet on the network layer using at least one network session key received from the join server, and forward the partially decrypted data packet to the application server; and

the application server is configured to decrypt the data packet on the application layer using at least one application session key received from the join server.

6 . The secure key management device of claim 1 , wherein the long range wide area network comprises a low power wireless access network domain comprising the end-device and a core network domain comprising the application server, and wherein the secure interface is configured for exchanging data with the join server outside the low power wireless access network domain and/or the wired core network domain.

7 . The secure key management device of claim 1 , wherein the secure interface is configured for exchanging data with the join server outside an address space of the LoRaWAN network, and the session information comprises at least one of a join nonce, a network ID and a device nonce.

8 . A method for generating session keys for use in a long range wide area network (LoRaWAN) comprising an end-device pre-registered with a secure key management device, a network server, an application server and a join server, the method comprising:

generating, by the secure key management device, based on at least one master key and a unique identifier of the end-device, at least one root key;

performing a pre-registration procedure before receiving a first request from the join server comprising providing the at least one generated root key to the end-device and providing, by the secure key management device, the join server with a registration message comprising the unique identifier of the end-device;

receiving, by the secure key management device from the join server via a secure interface, the first request comprising the unique identifier of the end-device and session information;

generating, by the secure key management device, based on the at least one master key previously generated by at least one processing component of the secure key management device and stored in a secure storage component of the secure key management device, and the unique identifier of the end-device and the session information comprised in the first request, at least one session key, wherein the secure storage component is distinct and separate from the at least one processing component; and

providing, by the secure key management device, the generated at least one session key via the secure interface to the join server.

9 . The method of claim 8 , wherein at least one network session key and at least one application session key is generated and provided to the join server by the secure key management device.

10 . The method of claim 8 , wherein the step of generating the at least one session key comprises:

generating, by the secure key management device, at least one root key of the end-device based on at least one first cryptographic function using the at least one master key stored in the secure key management device and the unique identifier of the end-device comprised in the first request; and

generating, by the secure key management device, the at least one session key based on at least one second cryptographic function using the at least one generated root key and the session information comprised in the first request.

11 . The method of claim 8 , wherein the end-device is pre-registered with the secure key management device before the step of receiving the first request in the pre-registration procedure, the pre-registration procedure comprising:

generating, by the secure key management device, the at least one master key and storing the at least one master key within the secure key management device;

generating, by the secure key management device, based on the at least one master key and the unique identifier of the end-device provided to the secure key management device, at least one root key; and

providing the at least one generated root key to the end-device.

12 . The method of claim 11 , wherein

the step of generating the at least one master key is repeated after a predetermined condition;

during the pre-registration procedure, version data related to the master key used for generating the at least one root key is provided to the end-device; and

the first request received from the join server further comprises the version data.

13 . The method of claim 12 , further comprising:

receiving, by the join server from the end-device, a second request comprising address information of the end-device;

providing, by the join server via the secure interface to the secure key management device, the first request based on the address information of the second request; and

forwarding the at least one session key received from the secure key management device via the secure interface to at least one of the network server and the application server.

14 . The method of claim 13 , wherein the address information of the second request comprises an end-device address identifier of the end-device, the method further comprising:

during the pre-registration procedure, providing, to the join server, the end-device address identifier as the unique identifier of the end-device;

mapping, by the join server, the end-device address identifier comprised in the second request to the unique identifier of the end-device; and

generating, by the join server, the first request based on the mapping of the end-device address identifier to the unique identifier.

15 . A data storage device storing instructions that, when executed by at least one processing device of a networked computing device, implements the steps for generating session keys for use in a long range wide area network (LoRaWAN) including an end-device pre-registered with a secure key management device, a network server, an application server and a join server, the steps comprising:

generating, by the secure key management device, based on at least one master key and a unique identifier of the end-device, at least one root key;

performing a pre-registration procedure before receiving a first request from the join server comprising providing the at least one generated root key to the end-device and providing, by the secure key management device, the join server with a registration message comprising the unique identifier of the end-device;

receiving, by the secure key management device from the join server via secure interface, the first request comprising the unique identifier of the end-device and session information;

generating, by the secure key management device, based on the at least one master key previously generated by at least one processing component of the secure key management device and stored in a secure storage component of the secure key management device, and the unique identifier of the end-device and the session information comprised in the first request, at least one session key, wherein the secure storage component is distinct and separate from the at least one processing component; and

providing, by the secure key management device, the generated at least one session key via the secure interface to the join server.