Method and reproduction unit for reproducing protected messages

1. A method for sending registered secure messages via a messaging system to a receiver device that is to be tested, wherein the messages are sent using serialized message packages, wherein the method has the following steps:

supplying first secure and still serialized messages from message packages for processing in a reproduction unit, wherein the first messages are provided by the payload of the message packages and, in turn, have payload data, a first counter value, and a first authenticator, wherein the following information is made available to the reproduction unit:

at least parts of a communication description for the receiver device to be tested or a data interpretation algorithm,

a second counter value for the receiver device to be tested, and

encryption information and a corresponding key;

by means of the reproduction unit:

in the first messages: reducing the data volume of the serialized messages by identifying the position of the payload data or the position of the first authenticator and removing at least the first authenticator and, where applicable, the first counter value from the secure and serialized first messages; and

deserializing the reduced first messages and creating second secure messages by adding the second counter value in each case or, where applicable, by replacing the first counter value with the second counter value, and creating and adding a second authenticator in each case by using the second counter value, the encryption information, and the key, and by using the communication description or the information obtained by applying the data interpretation algorithm; and

serializing the second secure messages and sending corresponding message packages to the receiver device to be tested.

2. The method according to claim 1 , wherein the payload data are identified by means of a lookup table created from the communication description, wherein the lookup table contains the message ID, the position of the payload data, and the length of the payload data.

3. The method according to claim 1 , wherein the first authenticator is identified by searching through the serialized data of the messages using the data interpretation algorithm, wherein the data interpretation algorithm is based on the detection of encrypted information in that said algorithm establishes contiguous values of maximum entropy.

4. The method according to claim 3 , wherein the algorithm is implemented in hardware.

5. The method according to claim 1 , wherein a message is sent in a manner spread across a plurality of message packages.

6. The method according to claim 1 , wherein the receiver device is an actual control device or a virtual control device, and wherein the messaging system is provided by an actual or a simulated bus communication system, by an actual or a simulated network, or by a combination of a bus system and a network, in particular by an automotive messaging system.

7. The method according to claim 1 , wherein the second counter value is in each case provided by the current counter value for the receiver device that is to be tested, or wherein the second counter value is provided by a counter value predetermined by a user or by an automatically calculated counter value.

8. The method according to claim 1 , wherein the payload data of the first secure messages are also encrypted using the first counter value, and the payload data are decrypted in the reproduction unit and re-encrypted by means of the encryption and the second counter value.

9. The method according to claim 1 , wherein the encryption information also comprises information for creating the second secure messages for testing purposes in such a way that the receiver device should detect them as being erroneous.

10. A reproduction tool for sending secure messages via a messaging system to a receiver device that is to be tested,

wherein the reproduction tool is connected via the messaging system to the receiver device that is to be tested,

wherein the reproduction tool is configured to obtain, from the payload of registered message packages, first secure and still serialized messages that are to be reproduced, to identify the position of the payload data or the position of a first authenticator in the first secure, still serialized messages, and to remove the authenticator and, where applicable, also the corresponding counter value from the serialized messages and generate a second authenticator by means of a second counter value, an encryption algorithm, and a key, and

wherein the reproduction tool is configured to generate second secure messages by adding the second authenticator to the first messages and by adding the second counter value, or by replacing the first counter value with the second counter value, and

wherein the reproduction tool is further configured to send the second secure messages to the receiver device, that is to be tested, via the messaging system in corresponding message packages.

11. The reproduction tool according to claim 10 , wherein the reproduction tool is configured as a unit for a hardware-in-the-loop (HIL) simulator or for a simulator for virtual validation.

12. A non-transitory computer readable medium comprising software for sending secure messages via a messaging system to a receiver device that is to be tested, the software storing instructions for executing the following operations:

obtain, from a payload of registered message packages, first secure and still serialized messages that are to be reproduced, to identify a position of the payload data or a position of a first authenticator in first secure, still serialized messages, and to remove an authenticator and, where applicable, also a corresponding counter value from a serialized messages and generate a second authenticator by a second counter value, an encryption algorithm, and a key, and

generate second secure messages by adding the second authenticator to first messages and by adding the second counter value, or by replacing the first counter value with the second counter value, and

send the second secure messages to the receiver device, that is to be tested, via the messaging system in corresponding message packages.

13. The non-transitory computer readable medium according to claim 12 , wherein the software is configured as an add on for a hardware-in-the-loop (HIL) simulator or for a simulator for virtual validation.