Systems, methods, and media for enhanced message-to-code data tie (emcdt) for electronic message authentication

A method for authenticating electronic messages, the method comprising:

• receiving, by a processor of a navigation receiver, a navigation message with navigation data, wherein the navigation message is received in a first data unit from a transmitter, wherein authentication of the navigation data requires use of a first key that is transmitted in a second data unit as part of an authentication service, and wherein the second data unit is after the first data unit;
• determining, by the processor, that a first transmitter identifier of the transmitter matches a second transmitter identifier for a particular previously authenticated message that was authenticated during transmission of a third data unit that precedes the first data unit;
• determining, by the processor, that a first version data identifier of the navigation messages matches a second version data identifier of the particular previously authenticated message;
• and
• authenticating the navigation data of the navigation message using (1) a tag corresponding to the particular previously authenticated message and (2) a second key that was used to authenticate the particular previously authenticated message.

A non-transitory computer readable medium having software encoded thereon, the software when executed by one or more computing devices operable to:

• receive a navigation message with navigation data in a first data unit and from a transmitter, wherein authentication of the navigation data is based on an authentication service that requires use of a first key that is transmitted in a second data unit, wherein the second data unit is a different data unit than the first data unit;
• determine that a first transmitter identifier of the transmitter matches a second transmitter identifier for a particular previously authenticated message that was authenticated during a third data unit that precedes the first data unit;
• determine that a first version data identifier of the navigation messages matches a second version data identifier of the particular previously authenticated message;
• and
• authenticate the navigation data of the navigation message using (1) a tag corresponding to the particular previously authenticated message and (2) a second key that was used to authenticate the particular previously authenticated message.