Analysis of the security of linear blinding techniques from an information theoretical point of view

We propose a novel model to characterize the security of linear blinding techniques. The proposed model relates the security of blinding to the possibility of estimating the blinded signals up to a certain signal-to-noise ratio (SNR). Practical upper bounds on the SNR are derived by relying on rate-distortion theory and evaluating the mutual information between the blinded and the plaintext signals. The proposed bounds allow to characterize the security of different blinding techniques, showing that multiplicative blinding techniques can not achieve the same level of security as additive ones. The proposed model provides a rigorous measure for evaluating the tradeoff between security and efficiency in practical secure signal processing algorithms.