Abstract: The first identification device located on first vehicle embeds a pre-detined pattern in an outgoing radiation and detects radiation incoming from a second identification device located on second vehicle. The two identification devices are identical to each other in their function. The first device phase-conjugates the incoming radiation and the result is combined with the pattern-containing radiation. The combination is then emitted toward the second device along the exact same optical path as the one taken by the incoming radiation in accordance with the principle of phase conjugation. The second device isolates the pattern from the combination radiation and, if the pattern is recognized, identifies the first vehicle as friendly. The the second device may engage in the same sequence of beamings as performed by the first device to identify itself (the second object to the first object.