Various embodiments relate to a demodulator configured to receive a legacy signal and a secured signal using orthogonal frequency division multiplexing (OFDM) modulation, including: an analog to digital converter (ADC) configured to receive an OFDM modulated signal; an fast Fourier transform (FFT) unit configured to receive the output of the ADC; a frequency de-mapper configured to map the output of the FFT to legacy frame samples and secured signal samples including a secured hash; a sample to bit converter, a channel de-interleaver, and a channel decoder configured to process the legacy samples to produce a legacy frame; frame checking logic configured to check the validity of the legacy frame and produce a frame validity signal; a de-channelization module configured to convert the sample rate of secured signal samples; a channel decoder configured to decode the converted secured signal bits; a frame selector configured to select specific portions of the input legacy frame to produce a secured frame; a hash module configured to hash and encrypt the secured frame; a hash comparator configured to compare the received secured hash to the hashed and encrypted secured frame configured to produce a hash compare signal; and attack detection logic configured to determine when a received OFDM signal has been attacked based upon the hash compare signal.