1. A device for watermarking a waveform, the device comprising:an overt symbol modulator to receive mapped overt data and provide overt data modulated in accord with an overt data modulation scheme;
a covert symbol modulator to receive mapped covert data and provide, using dither modulation and micro-amplitude modulation, covert data modulated in accord with a covert data modulation scheme;
a clock that operates with a jitter on the order of femtoseconds coupled to the overt symbol modulator and the covert symbol modulator;
a switch to receive the modulated covert data and the modulated overt data and forward the covert data and modulated overt data based on a signal indicating whether covert data is to be transmitted and/or the overt data is to be transmitted; and
transmission circuitry to produce an electromagnetic waveform of the modulated overt data and/or modulated covert data from the switch,
wherein the modulated overt data includes a constellation of symbols and the modulated covert data includes a symbol for every sub-constellation of symbols in the constellation of symbols, wherein the symbol is within a perimeter of the sub-constellation.