Industrial control system redundant communication/control modules authentication

A communications/control module, comprising:

• a first connection for communicatively coupling with at least one input/output module configured to be communicatively coupled to a field device, 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.

A communications/control module, comprising:

• a first connection for communicatively coupling with at least one input/output module configured to be communicatively coupled to a field device, 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.