Processing system, related integrated circuit, device and method

1. A processing system, comprising:

a first processing unit driven with a first clock signal;

a second processing unit driven with a second clock signal, wherein a frequency of the second clock signal is less than a frequency of the first clock signal;

a cryptographic coprocessor communicatively coupled to the first processing unit and the second processing unit, wherein the first processing unit, the second processing unit and the cryptographic coprocessor are in close proximity within the processing system;

a transmission system coupled between the first processing unit and the second processing unit, the transmission system providing a transmission path between the first and second processing units outside the cryptographic coprocessor;

the cryptographic coprocessor comprising:

a key storage memory for storing a cryptographic key;

a first interface configured to receive source data to be processed directly from the first processing unit;

a hardware cryptographic engine driven with the first clock signal that is configured to process the source data as a function of the cryptographic key stored in the key storage memory;

a second interface configured to receive a first cryptographic key directly from the second processing unit; and

a hardware key management circuit driven with the second clock signal that is configured to store the first cryptographic key in the key storage memory.

2. The processing system according to claim 1 , wherein the hardware cryptographic engine is configured to process the source data by selectively encrypting or decrypting the source data.

3. The processing system according to claim 2 , further comprising a communication interface connected to the first processing unit, wherein the first processing unit is configured to:

send the source data to the first interface requesting encryption of the source data;

read encrypted source data from the first interface; and

transmit the encrypted source data via the communication interface.

4. The processing system according to claim 3 , wherein the first processing unit is further configured to:

receive the encrypted source data via the communication interface;

send the encrypted source data to the first interface requesting decryption of the encrypted source data; and

read decrypted source data from the first interface.

5. The processing system according to claim 1 , wherein the hardware cryptographic engine is configured to support an Advanced Encryption Standard operation.

6. The processing system according to claim 5 , wherein the Advanced Encryption Standard operation comprises an Electronic Codebook encryption and decryption; a Cipher Block Chaining encryption and decryption; and/or a Cipher-based Message Authentication Code generation and verification.

7. The processing system of claim 1 , wherein the transmission system comprises:

a transmitter circuit configured to receive data to be transmitted and configuration information from the first processing unit; and

a receiver circuit configured to receive the data to be transmitted and configuration information from the transmitter circuit that is read by the second processing unit.

8. The processing system of claim 7 , wherein the transmission system further comprises:

a first register configured to receive and store the data to be transmitted and configuration information from the first processing unit and write the data to be transmitted and configuration information to the transmitter circuit; and

a second register configured to receive and store the data to be transmitted and configuration information from the transmitter circuit and write the data to be transmitted and configuration information to the receiver circuit.

9. The processing system according to claim 1 , wherein the processing system is part of an electronic system of a vehicle, the first processing unit, the second processing unit and the cryptographic coprocessor being located within the vehicle.

10. A processing system comprising:

a first processing unit driven by a first clock signal, the first processing unit having a first input/output and a separate second input/output;

a second processing unit having a first input/output and a separate second input/output, wherein a frequency of the second clock signal is less than a frequency of the first clock signal;

a cryptographic coprocessor communicatively coupled between the first input/output of the first processing unit and the first input/output of the second processing unit, wherein the first processing unit, the second processing unit and the cryptographic coprocessor are in close proximity within the processing system;

a transmission system coupled between the second input/output of the first processing unit and the second input/output of the second processing unit;

a non-volatile memory configured to store a first cryptographic key, wherein the second processing unit is configured to read the first cryptographic key from the non-volatile memory and send the first cryptographic key to the cryptographic coprocessor;

wherein the cryptographic coprocessor comprises:

a key storage memory for storing a cryptographic key;

a first interface configured to receive source data to be processed directly from the first input/output of the first processing unit;

a hardware cryptographic engine driven with the first clock signal and is configured to process the source data as a function of the cryptographic key stored in the key storage memory;

a second interface configured to receive the first cryptographic key directly from the first input/output of the second processing unit; and

a hardware key management circuit driven with a second clock signal and is configured to store the first cryptographic key in the key storage memory.

11. The processing system according to claim 10 , wherein the second processing unit is a microprocessor.

12. The processing system according to claim 11 , wherein the second interface is a special function register of the microprocessor.

13. The processing system according to claim 10 , further comprising a hardware configuration module configured to read a second cryptographic key directly from the non-volatile memory and send the second cryptographic key to the hardware key management circuit, wherein the hardware key management circuit is configured to decrypt the first cryptographic key using the second cryptographic key.

14. The processing system according to claim 13 , wherein the cryptographic coprocessor further comprises a third interface configured to receive the second cryptographic key, wherein the hardware key management circuit is configured to store the second cryptographic key in the key storage memory in response to the third interface receiving the second cryptographic key.

15. The processing system according to claim 10 , further comprising a further processing unit configured to transmit the source data to the first processing unit or directly to the cryptographic coprocessor.

16. The processing system according to claim 15 , wherein the non-volatile memory is not directly accessible by the further processing unit.

17. The processing system of claim 10 , wherein the transmission system comprises:

a transmitter circuit configured to receive data to be transmitted and configuration information from the first processing unit; and

a receiver circuit configured to receive the data to be transmitted and configuration information from the transmitter circuit that is read by the second processing unit.

18. The processing system of claim 17 , wherein the transmission system further comprises:

a first register configured to receive and store the data to be transmitted and configuration information from the first processing unit and write the data to be transmitted and configuration information to the transmitter circuit; and

a second register configured to receive and store the data to be transmitted and configuration information from the transmitter circuit and write the data to be transmitted and configuration information to the receiver circuit.

19. The processing system according to claim 10 , wherein the processing system is part of an electronic system of a vehicle, the first processing unit, the second processing unit and the cryptographic coprocessor being located within the vehicle.

20. A method of operating a local processing system, the method comprising:

communicating information from a first processing unit of the local processing system directly to a second processing unit of the local processing system, the first processing unit being a non-secure processing unit and the second processing unit being a secured processing unit, wherein the first processing unit is driven by a first clock signal and the second processing unit is driven by a second clock signal, the second clock signal having a frequency that is less than a frequency of the first clock signal;

providing source data to a first interface of the local processing system via the first processing unit of the local processing system;

providing a first cryptographic key to a second interface of the local processing system via the second processing unit of the local processing system;

processing the source data by selectively encrypting or decrypting the source data using the first cryptographic key to generate processed source data via a hardware cryptography engine, wherein the hardware cryptography engine is driven with the first clock signal; and

reading the processed source data from the first interface of the local processing system via the first processing unit of the local processing system.

21. The method according to claim 20 , further comprising:

sending the source data to the first interface of the local processing system requesting encryption of the source data;

reading encrypted source data from the first interface of the local processing system; and

transmitting the encrypted source data via a communication interface of the local processing system.

22. The method according to claim 20 , further comprising:

receiving encrypted source data via a communication interface of the local processing system;

sending the encrypted source data to the first interface of the local processing system requesting decryption of the encrypted source data; and

reading decrypted source data from the first interface of the local processing system.