Information processor, mobile body apparatus, and communication system

An information processor comprising:

• a memory storing a program, and
• at least one processor configured to execute the program to perform operations comprising:
• protecting at least a portion of a first communication in which a frame is transmitted or received cyclically;
• and
• incrementing a frame counter that increments a frame count value transmitted or received via the first communication for each frame, wherein
• the frame includes first packet data configured by one piece of packet data and second packet data configured by a plurality of pieces of packet data,
• protecting the first communication includes performing an arithmetic operation of a first message authentication code (MAC) using at least the frame count value and a portion or all of the first packet data,
• protecting the first communication includes performing an arithmetic operation of a second MAC using at least the frame count value and a portion or all of the second packet data, and
• at least one of the first packet data or the second packet data includes abnormality notification information in a case where there is abnormality in at least one of the frame count value or the frame counter,
• the abnormality notification information comprises the frame count value, and is set to a predetermined count value in a case where there is abnormality in at least one of the frame count value or the frame counter,
• the first MAC is transmitted or received in a case where the frame count value is not the predetermined count value, and the first MAC is not transmitted or received in a case where the frame count value is the predetermined count value, and
• the second MAC is transmitted or received in a case where the frame count value is not the predetermined count value, and the second MAC is not transmitted or received in a case where the frame count value is the predetermined count value.

An information processor comprising:

• a memory storing a program, and
• at least one processor configured to execute the program to perform operations comprising:
• protecting at least a portion of a first communication in which a frame is transmitted or received cyclically;
• incrementing a frame counter that increments a frame count value transmitted or received via the first communication for each frame, wherein
• the frame includes first packet data configured by one piece of packet data and second packet data configured by a plurality of pieces of packet data,
• protecting the first communication includes performing an arithmetic operation of a first message authentication code (MAC) using at least the frame count value and a portion or all of the first packet data,
• protecting the first communication includes performing an arithmetic operation of a second MAC using at least the frame count value and a portion or all of the second packet data, and
• at least one of the first packet data or the second packet data includes abnormality notification information in a case where there is abnormality in at least one of the frame count value or the frame counter;
• incrementing an additional frame counter that increments an additional frame count value every time the frame count value is reset to an initial value, wherein
• the frame count value is a frame number,
• only the frame number is stored in the first packet data, and the additional frame count value is not stored in the first packet data, and
• at least the frame number is stored in the second packet data.

A mobile body apparatus comprising:

• a memory storing a program, and
• at least one processor configured to execute the program to perform operations comprising:
• protecting at least a portion of a first communication in which a frame is transmitted or received cyclically;
• incrementing a frame counter that increments a frame count value transmitted or received via the first communication for each frame, wherein
• the frame includes first packet data configured by one piece of packet data and second packet data configured by a plurality of pieces of packet data,
• protecting the first communication includes performing an arithmetic operation of a first message authentication code (MAC) using at least the frame count value and a portion or all of the first packet data,
• protecting the first communication includes performing an arithmetic operation of a second MAC using at least the frame count value and a portion or all of the second packet data, and
• at least one of the first packet data or the second packet data includes abnormality notification information in a case where there is abnormality in at least one of the frame count value or the frame counter;
• incrementing an additional frame counter that increments an additional frame count value every time the frame count value is reset to an initial value, wherein
• the abnormality notification information comprises the frame count value, and is set to a predetermined count value in a case where there is abnormality in at least one of the frame count value or the frame counter, and
• the additional frame counter increments the additional frame count value every time the predetermined count value is set;
• and
• performing arithmetic operations of the first MAC and the second MAC using at least the additional frame count value.

A mobile body apparatus comprising:

• a memory storing a program, and
• at least one processor configured to execute the program to perform operations comprising:
• protecting at least a portion of a first communication in which a frame is transmitted or received cyclically;
• incrementing a frame counter that increments a frame count value transmitted or received via the first communication for each frame, wherein
• the frame includes first packet data configured by one piece of packet data and second packet data configured by a plurality of pieces of packet data,
• protecting the first communication includes performing an arithmetic operation of a first message authentication code (MAC) using at least the frame count value and a portion or all of the first packet data,
• protecting the first communication includes performing an arithmetic operation of a second MAC using at least the frame count value and a portion or all of the second packet data, and
• at least one of the first packet data or the second packet data includes abnormality notification information in a case where there is abnormality in at least one of the frame count value or the frame counter;
• the abnormality notification information comprises the frame count value, and is set to a predetermined count value in a case where there is abnormality in at least one of the frame count value or the frame counter,
• the first MAC is transmitted or received in a case where the frame count value is not the predetermined count value, and the first MAC is not transmitted or received in a case where the frame count value is the predetermined count value, and
• the second MAC is transmitted or received in a case where the frame count value is not the predetermined count value, and the second MAC is not transmitted or received in a case where the frame count value is the predetermined count value.

A non-transitory computer readable medium storing a program, the program being executable by a processor to perform operations comprising:

• protecting at least a portion of a first communication in which a frame is transmitted or received cyclically;
• incrementing a frame counter that increments a frame count value transmitted or received via the first communication for each frame, wherein
• the frame includes first packet data configured by one piece of packet data and second packet data configured by a plurality of pieces of packet data,
• protecting the first communication includes performing an arithmetic operation of a first message authentication code (MAC) using at least the frame count value and a portion or all of the first packet data,
• protecting the first communication includes performing an arithmetic operation of a second MAC using at least the frame count value and a portion or all of the second packet data, and
• at least one of the first packet data or the second packet data includes abnormality notification information in a case where there is abnormality in at least one of the frame count value or the frame counter;
• incrementing an additional frame counter that increments an additional frame count value every time the frame count value is reset to an initial value, wherein
• the abnormality notification information comprises the frame count value, and is set to a predetermined count value in a case where there is abnormality in at least one of the frame count value or the frame counter, and
• the additional frame counter increments the additional frame count value every time the predetermined count value is set;
• and
• performing arithmetic operations of the first MAC and the second MAC using at least the additional frame count value.

A non-transitory computer readable medium storing a program, the program being executable by a processor to perform operations comprising:

• protecting at least a portion of a first communication in which a frame is transmitted or received cyclically;
• and
• incrementing a frame counter that increments a frame count value transmitted or received via the first communication for each frame, wherein
• the frame includes first packet data configured by one piece of packet data and second packet data configured by a plurality of pieces of packet data,
• protecting the first communication includes performing an arithmetic operation of a first message authentication code (MAC) using at least the frame count value and a portion or all of the first packet data,
• protecting the first communication includes performing an arithmetic operation of a second MAC using at least the frame count value and a portion or all of the second packet data, and
• at least one of the first packet data or the second packet data includes abnormality notification information in a case where there is abnormality in at least one of the frame count value or the frame counter,
• the abnormality notification information comprises the frame count value, and is set to a predetermined count value in a case where there is abnormality in at least one of the frame count value or the frame counter,
• the first MAC is transmitted or received in a case where the frame count value is not the predetermined count value, and the first MAC is not transmitted or received in a case where the frame count value is the predetermined count value, and
• the second MAC is transmitted or received in a case where the frame count value is not the predetermined count value, and the second MAC is not transmitted or received in a case where the frame count value is the predetermined count value.