Systems, devices, and methods of the present invention facilitate secure communication by altering the set of symbol waveforms that may be in use in particular symbol times defined herein as Symbol Waveform Hopping. SWH may be enabled by selecting two or more modulation formats that have sufficiently comparable communication performance (e.g., occupied bandwidth and signal power efficiency), but characterized by symbol waveform alphabet that include different symbol waveform, so that the overall transmission/communication performance of data stream in a signal transmission channel of the system is not significantly affected by switching between modulation formats. Some or all of the symbol waveforms in each alphabet may not be present in other alphabets.