Industrial control system redundant communications/control modules authentication

1. A secure industrial control system, comprising:

one or more industrial elements, the one or more industrial elements including at least one input/output module operable to receive industrial sensor information or send control information to an industrial actuator or motor; and

a set of redundant communications/control modules that drive the one or more industrial elements, each of the redundant communications/control modules including at least one respective processor coupled to a respective non-transitory medium that stores instructions executable by the at least one respective processor; the set of redundant communications/control modules including a first communications/control module and a second communications/control module, the first and second communications/control modules both being communicatively coupled with the at least one input/output module and configured to monitor and control the at least one input/output module, the first and second communications/control modules being further configured to perform an authentication sequence, the authentication sequence including:

transmitting a request datagram from the first communications/control module to the second communications/control module, the request datagram including a first nonce, a first device authentication key certificate, and a first identity attribute certificate;

transmitting a response datagram from the second communications/control module to the first communications/control module, the response datagram including a second nonce, a first signature associated with the first and second nonces, a second device authentication key certificate, and a second identity attribute certificate;

transmitting an authentication datagram from the first communications/control module to the second communications/control module when the response datagram is valid, the authentication datagram including a second signature associated with the first and second nonces; and

transmitting a failed authentication datagram from the first communications/control module to the second communications/control module when the response datagram is invalid, the failed authentication datagram including a signature associated with the second nonce and an error message generated by the first communications/control module.

2. The industrial control system of claim 1 , wherein the authentication sequence performed by the first and second communications/control modules further comprises:

transmitting a responsive authentication datagram from the second communications/control module to the first communications/control module, the responsive authentication datagram including a signature associated with the first nonce and a success or failure message generated by the second communications/control module.

3. The secure industrial control system of claim 1 , wherein at least one of the first nonce and the second nonce comprises a random nonce generated by a true random number generator.

4. The secure industrial control system of claim 1 , wherein the second communications/control module is configured to generate the first signature associated with the first and second nonces by concatenating the first nonce and the second nonce, and signing the concatenation of the first nonce and the second nonce, and wherein the first communications/control module is configured to generate the second signature associated with the first and second nonces by concatenating the first nonce and the second nonce, and signing the concatenation of the first nonce and the second nonce.

5. The secure industrial control system of claim 1 , wherein the second communications/control module is further configured to validate the request datagram by verifying the first device authentication key certificate and the first identity attribute certificate.

6. The secure industrial control system of claim 1 , wherein the first communications/control module is further configured to validate the response datagram by verifying the first signature associated with the first and second nonces, the second device authentication key certificate, and the second identity attribute certificate.

7. The secure industrial control system of claim 6 , wherein the first communications/control module is configured to verify the first signature associated with the first and second nonces by concatenating the first nonce and the second nonce, cryptographically verifying the first signature associated with the first and second nonces with a public device authentication key, and comparing the locally generated concatenation of the first nonce and the second nonce with a cryptographically verified concatenation of the first nonce and the second nonce.

8. The secure industrial control system of claim 1 , wherein the second communications/control module, in response to receiving the authentication datagram from the first communications/control module, is configured to verify the second signature associated with the first and second nonces by concatenating the first nonce and the second nonce, cryptographically verifying the second signature associated with the first and second nonces with a public device authentication key, and comparing the locally generated concatenation of the first nonce and the second nonce with a cryptographically verified concatenation of the first nonce and the second nonce.

9. The secure industrial control system of claim 1 , wherein the first and second communications/control modules are configured to perform the authentication sequence in response to at least one of: a startup/reset event; an installation of the first communications/control module or the second communications/control module; a periodic time event; or scheduled time event.

10. The secure industrial control system of claim 1 , wherein the one or more industrial elements further include at least one of: a power module; a field device; a switch; a workstation; or a physical interconnect device.

11. A communications/control module, comprising:

a first connection for communicatively coupling with at least one input/output module operable to receive industrial sensor information or send control information to an industrial actuator or motor, the at least one input/output module being communicatively coupled with a second communications/control module;

a second connection for communicatively coupling with the second communications/control module;

at least one processor; and

a non-transitory medium bearing a set of instructions executable by the at least one processor, the set of instructions including instructions for performing an authentication sequence with the second communications/control module, including instructions to:

send a request datagram to the second communications/control module, the request datagram including a first nonce, a first device authentication key certificate, and a first identity attribute certificate;

receive a response datagram from the second communications/control module, the response datagram including a second nonce, a first signature associated with the first and second nonces, a second device authentication key certificate, and a second identity attribute certificate;

send an authentication datagram to the second communications/control module when the response datagram is valid, the authentication datagram including a second signature associated with the first and second nonces; and

send a failed authentication datagram to the second communications/control module when the response datagram is invalid, the failed authentication datagram including a signature associated with the second nonce and an error message.

12. The communications/control module of claim 11 , wherein the set of instructions further includes instructions to:

validate the response datagram by verifying the first signature associated with the first and second nonces, the second device authentication key certificate, and the second identity attribute certificate.

13. The communications/control module of claim 12 , wherein the set of instructions further includes instructions to:

verify the first signature associated with the first and second nonces by concatenating the first nonce and the second nonce, cryptographically verifying the first signature associated with the first and second nonces with a public device authentication key, and comparing the locally generated concatenation of the first nonce and the second nonce with a cryptographically verified concatenation of the first nonce and the second nonce.

14. A communications/control module, comprising:

a first connection for communicatively coupling with at least one input/output module operable to receive industrial sensor information or send control information to an industrial actuator or motor, the at least one input/output module being communicatively coupled with a second communications/control module;

a second connection for communicatively coupling with the second communications/control module;

at least one processor; and

a non-transitory medium bearing a set of instructions executable by the at least one processor, the set of instructions including instructions for performing an authentication sequence with the second communications/control module, including instructions to:

receive a request datagram from the second communications/control module, the request datagram including a first nonce, a first device authentication key certificate, and a first identity attribute certificate;

validate the request datagram by verifying the first device authentication key certificate and the first identity attribute certificate; and

send a response datagram to the second communications/control module when the request datagram is valid, the response datagram including a second nonce, a first signature associated with the first and second nonces, a second device authentication key certificate, and a second identity attribute certificate.

15. The communications/control module of claim 14 , wherein the set of instructions further includes instructions to:

receive an authentication datagram from the second communications/control module, the authentication datagram including a second signature associated with the first and second nonces; and

send a responsive authentication datagram to the second communications/control module, the responsive authentication datagram including a signature associated with the first nonce and a success or failure message.

16. The communications/control module of claim 15 , wherein the set of instructions further includes instructions to:

verify the second signature associated with the first and second nonces by concatenating the first nonce and the second nonce, cryptographically verifying the second signature associated with the first and second nonces with a public device authentication key, and comparing the locally generated concatenation of the first nonce and the second nonce with a cryptographically verified concatenation of the first nonce and the second nonce.

17. The communications/control module of claim 14 , wherein the set of instructions further includes instructions to:

generate the first signature associated with the first and second nonces by concatenating the first nonce and the second nonce, and signing the concatenation of the first nonce and the second nonce.

18. The secure industrial control system of claim 1 , wherein the first communications/control module is configured to initiate the authentication sequence in response to an installation of the second communications/control module.

19. The secure industrial control system of claim 1 , wherein the second communications/control module is configured to take over monitoring and controlling the at least one input/output module when the first communications/control module experiences a failure event.

20. The secure industrial control system of claim 1 , wherein the first communications/control module is further configured to at least partially disable or restrict communications of the second communications/control module when the second communications/control module fails to authenticate with the first communications/control module.