Mobile multilateration systems and related methods are disclosed. An example method includes accessing multilateration data relating to a first aircraft using a time-difference-of-arrival determiner of a second aircraft; processing the multilateration data at the second aircraft to determine a calculated position of the first aircraft; comparing the calculated position of the first aircraft to an asserted position of the first aircraft stored at the second aircraft; and in response to the comparison, determining if the calculated position and the asserted position are within a threshold of one another using the time-difference-of-arrival determiner of the second aircraft to determine an authenticity of the first aircraft.