Parameter-adaptive identical synchronization disclosing Lorenz chaotic masking

Abstract

A parameter-adaptive rule that globally synchronizes oscillatory Lorenz chaotic systems with initially different parameter values is reported. In principle, the adaptive rule requires access to the three state variables of the drive system but it has been readapted to work with the exclusive knowledge of only one variable, a potential message carrier. The rule is very robust and can be used to trace parameter modulation conveying hidden messages. The driven system is defined according to a drive-driven type of coupling that guarantees synchronization if parameters are identical. From any arbitrary initial state, the parameters of the driven system are dynamically adapted to reach convergence to the drive parameter values. At this point, synchronization mismatch or parameter tracing is used to unmask any potential hidden message.