Information security is one of the most important areas in wireless communication systems. Traditional information security methods are based on the upper layers of the open systems interconnection model (OSI) protocol stack, but their reliability is significantly reduced for scenarios where legitimate and illegitimate users share a common physical environment. In this article we develop an OFDM (orthogonal frequency-division multiplexing) communication system where instead of traditional orthogonal transformations (OT), for example, Walsh, Haar, Fourier transforms, their fractional (FOT) or multiparameter implementations (MPOT) are used. Such transformations depend on a finite set of independent parameters (in case of fractional OT) or (in case of MPOT), which change their form. When , or the transformation takes the form of the classical OT, and when , or degenerates into the identical transformation. Successful information exchange requires knowledge of the parameters of the currently used FOT or MPOT, which may change periodically. The simulation results of OFDM system using single-parameter Fourier-Bargmann transform (FrFBT) show that the proposed OFDM system provides better security against unauthorized access to information compared to the traditional OFDM system.