A symmetric data encryption system configured to receive a data stream to be encoded; to relate segments of the data stream with a predetermined distortion-inducing amplitude of light to encrypt the data stream; to transmit the data stream; to decrypt the data stream by compensating for the value induced by the distortion-inducing amplitude of light; wherein the distortion-inducing amplitude of light relates to different wavelengths of light emitted by one or more of a plurality of light sources in a non-uniform manner so the effect of the distortion-inducing amplitude of light is difficult to predict, thereby providing obfuscation and encryption of the data stream.